Michael Curry, the first African-American head of the US Episcopal Church, will preach at Prince Harry and Meghan Markle's wedding on Saturday.

Renowned for his stirring preaching style, self-deprecating humour and raucous laughter, Curry is the presiding bishop of the Episcopal Church — the Church of England's sister body in the US.

While the choice reflects Ms Markle's own African-American heritage and the couple's transatlantic relationship, it is a break from tradition in that typically royal preachers are senior CofE clergy.

On top of that Curry is an outspoken figure on issues ranging from civil rights and Donald Trump's presidency, to same-sex marriage in church and poverty. The couple's decision to ask Curry is made all the more interesting by the fact they do not have a personal relationship with him. Rather the decision was made in consultation with the archbishop of Canterbury, Justin Welby, who baptised Ms Markle into the Church of England in a private ceremony and will officiate at the wedding.

A spokesman for Kensington Palace said of the Prince and Ms Markle's choice: 'The couple and the archbishop discussed a number of possibilities for a preacher.

'Whilst Bishop Curry is not personally known to the couple, it was felt that given the fact that he the Presiding Bishop of the Episcopal Church as well as a wonderful speaker and preacher, it would be highly appropriate for him to be invited to speak.'

Welby warmly welcomed the announcement.

Welby has a close relationship with his American counterpart, despite backing the decision to impose sanctions on the Episcopal Church for allowing same-sex marriage. The 'consequences' came after the Episcopal Church first consecrated an openly gay bishop, Gene Robinson, in 2003, and officially authorised gay marriage in 2015.

Curry, who is descended from slaves and sharecroppers in North Carolina and Alabama, has spoken of how his background influences his own passionate defence of same-sex marriage in church.

Last May he filed a 'friend of the court' briefing in support of transgender people's right to use the bathroom of their choice. 

And in response to the 2016 decision against the Episcopal Church, which was made by the other leaders of the worldwide Anglican Communion, most of who are from the socially conservative global south, Curry issued a robust commitment to his pro-LGBT stance.

'Our commitment to be an inclusive church is not based on a social theory or capitulation to the ways of the culture, but on our belief that the outstretched arms of Jesus on the cross are a sign of the very love of God reaching out to us all,' he said.

'For fellow disciples of Jesus in our church who are gay or lesbian, this will bring more pain. For many who have felt and been rejected by the church because of who they are, for many who have felt and been rejected by families and communities, our church opening itself in love was a sign of hope. And this will add pain on top of pain,' he added.

Speaking to his fellow Anglican leaders who had imposed the sanctions, he added: 'I stand before you as a descendant of African slaves, stolen from their native land, enslaved in a bitter bondage, and then even after emancipation, segregated and excluded in church and society. And this conjures that up again, and brings pain.'

But it is not just sexuality that Curry is outspoken on.

Shortly after preaching at the royal wedding on May 19, Curry will take a leading role in a march on Washington to denounce Trump's 'America First' policies as 'heresy'.

The demonstration outside the White House on May 24 is aimed at 'reclaiming Jesus' after Trump's administration has received unfettered support from leading white evangelical figures. It is accompanied by a damning statement, signed by Curry, which is heavily critical of developments in US public life.

'We are living through perilous and polarising times as a nation, with a dangerous crisis of moral and political leadership at the highest levels of our government and in our churches. We believe the soul of the nation and the integrity of faith are now at stake,' it begins.

'We reject the resurgence of white nationalism and racism in our nation on many fronts, including the highest levels of political leadership.'

Signatories also reject 'misogyny, the mistreatment, violent abuse, sexual harassment, and assault of women that has been further revealed in our culture and politics, including our churches, and the oppression of any other child of God'.

The declaration represents a comprehensive attack on President Trump's agenda, continuing: 'We strongly deplore the growing attacks on immigrants and refugees, who are being made into cultural and political targets, and we need to remind our churches that God makes the treatment of the "strangers" among us a test of faith (Leviticus 19:33-34). We won't accept the neglect of the well-being of low-income families and children, and we will resist repeated attempts to deny health care to those who most need it. We confess our growing national sin of putting the rich over the poor. We reject the immoral logic of cutting services and programmes for the poor while cutting taxes for the rich.'

In an apparent personal reference to Trump – without naming him – it says: 'We reject the practice and pattern of lying that is invading our political and civil life. Politicians, like the rest of us, are human, fallible, sinful, and mortal. But when public lying becomes so persistent that it deliberately tries to change facts for ideological, political, or personal gain, the public accountability to truth is undermined.'

None of this is to say that Prince Harry and Meghan Markle are making a deliberate statement in their choice, although Ms Markle herself has branded Trump 'divisive' and 'misogynistic'.

But they are hardly going to be ignorant of Curry's profile and the implications that will be drawn from their choice.

The service will be broadcast to millions around the world. For Curry, who refers to himself as the CEO of the Episcopal Church – the Chief Evangelism Officer – the opportunity to talk passionately about what he calls the Jesus Movement won't be missed.