Opponents of assisted dying have reacted with horror after doctors in Holland performed the euthanasia of a 29-year-old woman who was suffering from mental health problems but was physically fit.

Aurelia Brouwers, who wrote movingly on her blog about her plight, was given a lethal injection less than a month after winning an eight-year battle to end her life, the Catholic Herald reported.

Brouwers, who had spent nearly three years in a mental health institution and another two-and-half years in prison, argued that her bouts of severe depression made her life intolerable and led her to attempt suicide, and commit self-harm and arson.

She said that she suffered from a borderline personality disorder, addiction and anxiety disorders and that she heard voices.

Brouwers died in the company of friends and family after announcing on Facebook just two hours earlier: 'I am finally dying today.'

She had become in recent years a prominent campaigner in the Netherlands for euthanasia for the mentally ill and the young, and had pressed Dutch MPs further to liberalise its 16-year-old law.

Brouwers claimed on her blog that she was working closely with Dignity in Dying, the UK campaign group formerly known as the Voluntary Euthanasia Society, in setting up and co-managing international Facebook groups to press for the legalisation of euthanasia around the world. However, Dignity in Dying denied this, saying it had had no contact with her. In a statement it said: 'Dignity in Dying campaigns in the UK to change the law on assisted dying for terminally ill, mentally competent adults only. Aurelia Brouwers would not be eligible for assisted dying under the law change we are seeking, which would allow dying people of sound mind to choose the manner and timing of their deaths.'

Brouwers wrote on her blog: 'Regarding euthanasia, I think everyone should have the chances I have.'

On January 8 on her blog she called for 'openness and broader legislation that makes more people with psychiatric problems, and especially young people, have a chance of euthanasia and do not have to resort to suicide'.

She added then: 'Although I said goodbye to life long ago, there is still time to say goodbye. And that is saying goodbye to the people around me. The people I care about: my father, my friends. That is the hardest thing I notice. Friends who come for the last time. When they leave, it becomes quiet for a moment...what do you say at such a moment? "Bye"?'

She later described preparing for her death on Friday, January 26 after she was given permission on December 31, declaring that 'there is no muscle in my body' that doubted her decision to end her life by lethal injection.

'I only want to go one way and have strived for that for eight years and that is death,' she said.

She wrote that she believes that she will go to heaven, saying: 'I believe that after my death I will go to heaven.'

On December 6, the day she discovered that her death could go ahead, she wrote: '8 years of fighting for this. Now I can die in dignity. This is the best gift I have ever received.'

British political and church figures reacted with shock.

Dr Peter Saunders, the campaign director of the Care Not Killing Alliance, told Christian Today: 'This tragic case illustrates the impossibility of legislating to allow euthanasia without leading to an expansion of categories of people to be included. We have seen the Netherlands beginning with mentally competent adults with terminal illnesses leading now to the killing of children, people with dementia and those with mental illnesses. Once we accept the principle that it is justifiable in some circumstances to take the life of a person whose life is judged not to be worth living incremental extension with inevitably follow. It cannot be controlled.

'Britain should take warning. The only workable law is what we have at present – a blanket ban on all euthanasia and assisted suicide with judges exercising discretion and tempering justice with mercy in sentencing hard cases. Our law does not need changing.'

Joe Ronan, from Catholic Voices, also old Christian Today: 'It's very sad. You've got a physically fit 29-year-old wanting to take her life and, it appears, being encouraged to do that, being closely related to the campaigners for euthanasia. It shows that all assurances about lines and protections that these campaigns have talked about don't really stack up.

'It's certainly an example about how once the rule comes in the protections are chipped away. All the reassurances we have from those in favour that we have protections will be chipped away over time. Part of that is because at the moment in the UK we have an absolute value of life.

'Once you cross the line and say well, in this case or that case there is a relative judgment, then you have this problem that anyone who deviates from what might be regarded as normal might be under pressure to end their life. First it's the terminally ill, then it's people who don't have sufficient quality of life, whatever that might mean. All of us can ask where to do we fit in that, so it shows the value of a very strong line between supporting those who are dying and actually killing them. This shows how important it is to have an absolute definition of the value of life.

'It also shows, in this country we have shown a lot of interest in the mental health of the young, and people want to be helped and loved and supported, and that's what we should be doing.

'The prime desire of people is not necessarily to die but to end their suffering and that is down to us.'

Lord Carlile, the co-chairman of Living and Dying Well, a parliamentary group opposed to euthanasia, told the Catholic Herald: 'I am horrified. This is a case which illustrates the grave dangers presented by euthanasia and assisted dying.'

He added: 'Doctors should not be implicated in it and I would be very surprised if British doctors considered it as falling within their ethical matrix.'

Fiona Bruce, the Conservative MP for Congleton and the chair of the All Party Parliamentary Pro-Life Group, said that one in four Britons 'experience mental health problems at some time in their life'.

'What is then needed, as it was for this young woman, is treatment not termination,' she added.

'The tragedy of her situation shows why it would be so dangerous for us this country to heed the voices – few but shrill – of those calling for euthanasia to be legalised here.'

She went on: 'On a personal level, it is tragic. On a political level, it is shameful.

'In the UK parliament, two years ago, after listening particularly carefully to the concerns of healthcare professionals, disabled people and other vulnerable groups, MPs voted to strongly reject a move in the UK towards legalising euthanasia.

'Now, far from helping those with mental health problems to die, the UK government is investing more money than ever in supporting those with mental health problems, and all parties are working together to remove the stigma around mental health problems and ensure that our healthcare and our society is better able to help anyone facing these challenges to live a full life.'

The number of mental health patients killed by lethal injection in Holland has quadrupled in just four years, figures there show, with euthanasia deaths now exceeding more than 6,000 cases annually, representing a leap of 50 per cent in five years.

According to the Catholic Herald, they include a 41-year-old alcoholic who said drink had turned his life into a 'cocktail' of misery and a female victim of child sex abuse who claimed she was unable to live with the subsequent trauma.

Euthanasia and assisted suicide are technically illegal under Dutch law, but are not punishable if doctors observe carefully defined criteria, which are supposed to act as safeguards. These include a request for euthanasia made freely by a mentally competent adult who is suffering unbearably and hopelessly.

There must also be no realistic alternative to euthanasia, and at least one other doctor must be consulted before the procedure can go ahead. After the death, the case must be reported to a review committee to ensure due diligence has been observed.

The legal situation is controversial in the country, with critics arguing that the law allows euthanasia on demand.

Last week, a Dutch euthanasia regulator resigned her position in protest at the killings of patients suffering from dementia. Berna van Baarsen objected to 'a major shift' in the interpretation of her country's euthanasia law to incorporate lethal injections for increasing numbers of dementia patients.

This came after the resignation in 2014 of Professor Theo Boer, a regulator who warned British parliamentarians not to follow the Dutch example.

Police in Holland last year launched their first investigation into a euthanasia death after an elderly woman with dementia was drugged and pinned down while injected with lethal drugs after allegedly consenting to a doctor-assisted death some years beforehand.

Assisted dying remains illegal in the UK, despite ongoing campaigns to legalise it.

Last year, the Catholic Church in England and Wales laucnhed an acclaimed website called The Art of Dying Well.