In fact, during all their premierships, the number of new laws concerning hate speech and equality regulations have shot up - thus shrinking the space for public debate.

Chillingly, Christians like those who go to Strasbourg today above have been sacked and disciplined for expressing their views. Roman Catholic adoption agencies have been forced to close or conform under the notorious Sexual Orientation Regulations of 2007, which decreed that Catholic adoption agencies could no longer follow their faith convictions by placing children with married couples, and have to allow homosexual couples to adopt, too.

In 2008, two Christian ministers were even threatened with arrest after handing out gospel leaflets in Birmingham, with police officers telling them their actions amounted to a 'hate crime'.

The tolerance which philosophers Voltaire and JS Mill wrote about in the 18th and 19th centuries allowed competing and fiercely opposed views to occupy the public square. The elusive value of 'tolerance' was more than a vague and wishy-washy buzzword.

But David Cameron has turned the value of 'tolerance' on its head.

Only two months ago he championed the right of Christians to wear crosses in Parliament in response to a question by one of his own MPs, David Davis, on these European cases.

Yet at the same time he was making that statement, his lawyers were drafting a legal submission to Strasbourg which opposes the rights of all these Christians. These lawyers are expected to speak against the right to wear the cross at court today, saying that the Christian faith doesn't demand it, and that it is up to the individual concerned.

Likewise, Government lawyers will also say that it is not necessary for Christians to demonstrate disapproval of gay relationships in order to maintain their faith.

We have to question, then, whether Cameron's initial words of support mean anything at all, given that his lawyers are telling two of those involved in today's case, Shirley Chaplin and Nadia Ewedia, that their religious freedom is merely guaranteed by their right to seek alternative employment.

Unsurprisingly, this is a view that has been expressed before by Equalities Minister, Lynne Featherstone, during the passage of the Equality Act in 2010, when she said that public sector workers with faith convictions should simply 'make different choices about their careers'.

I have to question whether we are now in a position that faith is a bar to public service. How this would appall the greater social reformers of the past such as William Temple and Lord Shaftesbury - among many others - whose Christian faith was the very reason they sought justice for others.

It has not always been like this.

When controversial legislation has been introduced in the past around, say, the relaxing of Sunday trading laws or the Abortion Act, exemptions were written into the law to respect strongly-held religious convictions. In the case of Sunday trading, those who wanted to worship were exempted from the need to work. In the case of the Abortion Act, medical staff who felt abortion was wrong were excused from performing or assisting in them.

In the past, there was space for negotiation between individuals and their employers, but the burden of ever-increasing regulation has meant that questions of conscience and freedom are neglected in favour of conformity.

The fact is that the Government and its predecessors have had plenty of opportunity to ensure that their warm rhetoric for religious believers was converted into action - to ensure that those like Shirley Chaplin could wear an entirely inoffensive cross to work.

Now, it is left to the European Court in Strasbourg to negotiate these complexities.

While it would surely have been easier for our own Government to exercise some common sense and legislate for a 'reasonable accommodation' of the rights of British Christians, we must now rely on judges to enter religious territory - an area in which they have never been known to have any expertise.

Only last year, historian David Starkey talked on BBC's Question Time about recent cases involving Christian foster carers and bed and breakfast owners, cases in which they had been discriminated against based on their religious views. Starkey warned that a new intolerance was emerging.

'It seems to me that what we are doing is producing a tyrannous new morality that is every bit as oppressive as the old,' he said.

I have often said that Christians have acted like 'doormats' for too long in a culture which owes so much to the formation of Christian faith.

Now is the time to stand up and be counted in support of 'tolerance', freedom of expression and worship, in the face of these new heresy trials.

By Lord Carey is the former Archbishop Of Canterbury