Image copyright Reuters

It has never been more politically fashionable, or mainstream, to be socially liberal - particularly around the subject of homosexuality.

So little wonder the new leader of the only party in Parliament with the word "liberal" in its title, who also happens to be a Christian, faces a few questions about how his politics and faith interact.

Appearing on Channel 4 News, Tim Farron was asked three times if he believes homosexual sex is a sin.

Three times, he didn't give a direct answer, instead choosing to say "my firm belief is we are all sinners".

'Taken aback'

Plenty of Liberal Democrats who actively campaign for the rights of gay, lesbian, bisexual and transgender people have sought to offer Mr Farron their support.

But others are worried.

Still bruised by its crushing losses at the general election, Mr Farron's critics don't want to publicly clash with him just hours into his leadership.

But those critics are there.

"I was quite taken aback when I watched the interview, given he must have known he would be asked about it," a former Lib Dem MP told me.

"The fact that he thinks we are all sinners isn't much comfort to those of us who firmly believe there's nothing wrong whatsoever with homosexuality," they said.

"He needs to be honest about his Christian convictions, instead of trying to be too much like a politician about it. There are those of his faith and others that would agree with him, that it is a sin. He should say it. At least that would have the benefit of him being honest."

'Not a homophobe'

Others within the party are concerned that Mr Farron's new status as a party leader, albeit one with only eight MPs, may mean this isn't the last time his own moral code, influenced by his faith, becomes political news.

"I think the issue is, could a topic arise in which what was being asked in Parliament had some moral element to it? He may well have a dilemma of that kind," another senior party figure told me.

"This is difficult for him, and will no doubt have provoked some soul searching," Lib Dem activist Sarah Brown told me.

Image copyright PA Image caption Tim Farron was elected as Lib Dem party leader on Thursday

Sarah sits on the executive of LGBT+ Liberal Democrats, which describes itself as the party's "sexual and gender identity minorities group."

A former city councillor in Cambridge, she was for many years the only openly transgender elected politician in the UK.

"Tim is coming in for a lot of flak about this and is being singled out, but he is not a homophobe. I have talked to him about this," Sarah said, when she rang me back from her holiday, so keen was she to emphasise she was relaxed about Mr Farron's beliefs.

Individual rights

Mathew Hulbert, a former Liberal Democrat councillor from Barwell in Leicestershire, whose Twitter profile includes a picture of him with Mr Farron, was unequivocal.

"I am a gay man and I have 100% certainty that my friend Tim Farron supports my equality under the law. That's it," he wrote.

Another Lib Dem and LGBT activist, Jordan Williams from Thanet in Kent, blamed what he called an "over dramatised media", writing: "Who knew that someone's faith obviously dictates whether they can lead a party or not."

It is a point Mr Farron made himself on Channel 4 News.

"It is a peculiar thing to say, that someone who happens to be a member of a religious group, who is a Christian, can't be a liberal. Exactly the opposite.

"To be a member of a minority group of any kind is to understand in a very clear way why it is that every minority, every individual's rights matter."

Intellectually, that is how Mr Farron ties together his religious and political beliefs.

Farron's challenges

But some of his colleagues are fretting about the practical consequences of this for their party.

"Our tradition in Parliament as Liberal Democrat MPs was to allow our colleagues on a range of issues which drew on our consciences to reach a decision on how to vote, and act, based on personal choice," a senior party figure told me.

"I suspect our party's activists would take a less tolerant attitude," he said.

And therein lies the personal - and political - challenge, for the new Liberal Democrat leader.