Ann Widdecombe has called on Christians to put pressure on the UK government to take action against persecution of Christians overseas – and to stop it developing here.

Speaking at an event held on Tuesday in south London, the former government minister and media personality warned that today's "small scale persecution" of UK Christians could dramatically worsen unless people began to "fight back".

Her message calling on Christians to "be extremely vigilant" was delivered to more than 200 people at St Mary's Church, Croydon.

The event was organised by Aid to the Church in Need, the Catholic charity for persecuted and other suffering Christians.

The former MP, who was speaking on the 20th anniversary of her conversion to Catholicism, said: "It's very easy to look at extreme cases abroad, to say thank God we don't have that here and then to overlook what we do have here, which is an increasing intolerance and marginalisation towards, and of, Christians."

Miss Widdecombe, who in 2011 was appointed ACN UK's special envoy for religious freedom, called on the UK government to "attach strings" to overseas aid to bring pressure to bear on countries where Christians are oppressed.

Saying that most countries where the state persecutes Christians receive UK government assistance, she added: "It was only a few months ago that the government said quite plainly that it would, when looking at its aid budget, take cognisance of whether a country had a record of persecuting or of tolerating homosexuals.

"Now if it can do it for those groups it can do it for Christians.

"And when it gives aid it can say to countries, we will withdraw that aid or we will reduce that aid if you carry on persecuting Christians."

Stressing the need to tackle state persecution, she said: "We are not talking about odd groups of zealots who might, in contravention of their country's law, perpetrate acts of violence against Christians or against Christians' properties, we are talking about where a state allows its own forces and agencies of law and order, such as its police force, to actually practise and promote persecution of a particular group."

She added: "The more representations that we make to the politicians, the more likely it is that pressure will be put on government not only to attach strings to its aid, but to raise it diplomatically."

Miss Widdecombe, Conservative MP for Maidstone and the Weald from 1987 to 2010, said the best way to do this was to write an individual letter about a specific country to your MP.

Turning to the UK, she said the main causes of "persecution" against Christians were equality legislation "and the over interpretation of it" and the view "that refusing to offend other faiths somehow involves surrendering our own".

Stating that anti-Christian "persecution" was new in the UK and was far worse abroad, she said: "If the small beginnings are not resisted then they grow into something much bigger."

She cited cases of discrimination of UK Christians in the workplace.

One involved an employee demoted for criticising gay marriage in private and another disciplined for wearing a small cross at work.

Referring to the latter, Miss Widdecombe added: "But isn't it odd that the person next to them can be wearing a hijab and the person a few rows down can be wearing a turban – and so they should be wearing their hijabs and so they should be wearing their turbans – but therefore so should the Christians be wearing their crosses."

She said: "If we all simply refuse to hide our crosses, refuse to refrain from saying things like 'God bless you' and 'Would you like me to pray for you?'…

"And if we all refuse to be cowed and bullied by that then we will be making a major contribution to the survival of and the thriving of Christianity in this country – which must not become a very tiny minority pursuit practised behind closed doors.

"But that is what it is in some other countries; even where it's not such a tiny minority it is driven behind closed doors."

Earlier, the MP praised ACN saying: "One of the reasons why I am so glad to be supporting Aid to the Church in Need is that there really are things that we can do [to help persecuted Christians] that over time bear fruit."

Source: Aid to the Church in Need