Justice Jeremy Cooke, who jailed Sarah Catt for eight years, one of at least five judges associated with Christian group

A judge who criticised UK abortion policies while sentencing a woman to eight years in prison for performing her own abortion at a late stage in her pregnancy is one of at least five members of the judiciary with links to a Christian charity which has campaigned for more conservative abortion laws.

There has been surprise at the severity of the sentence Justice Jeremy Cooke imposed on Sarah Catt, who took a drug when she was 39 weeks pregnant to cause an early delivery and pleaded guilty in July to administering a poison with intent to procure a miscarriage. Catt told police that she buried the remains but has refused to disclose the location.

In remarks that some commentators have criticised, he told her: "There is no mitigation available by reference to the Abortion Act, whatever view one takes of its provisions which are, wrongly, liberally construed in practice so as to make abortion available essentially on demand prior to 24 weeks with the approval of registered medical practitioners."

Cooke, a member of the Lawyers' Christian Fellowship (LCF) and one of the organisation's vice-presidents until December 2010, previously caused controversy when he jailed a woman for the attempted murder of the Labour MP Stephen Timms and appeared to contrast the politician's devout Christian faith with the values of the Muslim woman, who had been radicalised by an al-Qaida preacher.

"I understand that [Timms] brings to bear his own faith which upholds very different values to those which appear to have driven this defendant," Cooke said. "Those values are those upon which the common law of this country was founded and include respect and love for one's neighbour, for the foreigner in the land, and for those who consider themselves enemies, all as part of one's love of God."

The LCF, an organisation with a limited public profile but which has more than 2,500 members and a growing presence in graduate law schools, has been heavily involved in socially conservative causes including campaigning for a change in abortion laws. It states that one of its objectives is "applying God's justice on the ground".

The most senior member of the judiciary in the LCF, the influential high court judge Mark Hedley, is widely respected by peers – as is Cooke – but has admitted it can be difficult to square his beliefs with work as a judge.

"One of the difficulties of being a Christian within the law is that you're administering a system which doesn't claim to be Christian and the standards which law expects of people are often much less and rather different from the standards that Christians expect of themselves," he says in an interview for a religious education website.

"So that does lead to conflicts from time to time but at the end of the day we have to accept that we are put in a society and we have to live in the society in which God has placed us and we all have to play our roles in ensuring that that society works."

A number of other judges are associated with the LCF. They include a number of circuit court judges: John Stuart Colyer (now retired), who is listed in Who's Who as a vice-president from 1993, David Richardson, who has addressed annual conferences of the LCF's Student and Young Lawyers' (SYL) section, and Peter Collier. Asked how many judges were members of the LCF, and who they were, the fellowship responded by saying that it would be in breach of the Data Protection Act if it named members.

But while there is no suggestion that lawyers and judges associated with the LCF have been anything other than professional in their work, there has been unease among secular campaigners about its role.

Terry Sanderson, the president of the National Secular Society, said: "The Lawyers' Christian Fellowship appears to have a large number of influential legal representatives among its members. It purports simply to promote Christian fellowship among them, but one of its stated primary objectives is 'applying God's justice on the ground'. What does that mean when it comes to judges? Does it mean that 'God's law' – whatever that might be – will trump for them the democratically agreed laws of this country?

"There is nothing wrong with a judge being a Christian, but that is a very different thing to being a 'Christian judge' who wants to apply biblical principles to judgments when those principles might not accord with the civil law that he or she is charged to uphold."

In another interview, Hedley was said to be keen not to overplay the distinctiveness of being a Christian in the law, stating that a Christian and a humanist judge would reach the same conclusion in the vast majority of cases.

In practice, secularists have been among those who have admired his handling of highly emotive cases, notably that of a severely brain-damaged baby boy who Hedley ruled could be allowed to die even though his devoutly religious parents wanted him to be kept on a life-support system.

On another occasion, there was approval in the rightwing press and among Christian campaigners for his comments in a case in which a gay man and his lover took the lesbian mother of his children and her partner to court for access rights. The judge reportedly expressed frustration at the "lack of sufficient vocabulary to explain the true nature of the relationships" and said the case "provides a vivid illustration of just how wrong these arrangements can go".

Asked about suggestions that there could be a conflict of interest in cases such as the one involving Cooke, the LCF said: "The only membership requirement for the Lawyers' Christian Fellowship is agreement with its broad basis of faith. On issues outside the basis of faith members may, but do not necessarily, have the same views as the leadership of the organisation. There is no conflict between membership of the LCF and judicial office."

The Judicial Communications Office, which represents judges in England and Wales, said Cooke had no further comment to make on his sentencing remarks.

The official Guide to Judicial Conduct, issued by the Judges' Council of England and Wales, states that judges' active involvement in community groups such as educational, charitable and religious organisations "is not necessarily inappropriate and may confer a public benefit". But it adds that "care should be taken that it does not compromise judicial independence or put at risk the status or integrity of judicial office".

A persistent area of controversy is the relationship between the LCF and a socially conservative campaign group, Christian Concern, which other evangelical Christians increasingly regard as extreme.

Christian Concern, which encompasses the Christian Legal Centre, was established in 2008 by Andrea Williams, the LCF's former director of public policy, who reportedly said it was done "so as not to jeopardise the charitable status of the LCF".

The fellowship's website retains a link to Christian Concern, which has been at the forefront of some of the most high-profile campaigns on issues including abortion and gay rights. It also seeks to provide "a Christian response" to what it describes as the growing influence of radical Islam in the UK, which it says "has great repercussions for all of us".

In May, the Law Society cancelled a booking for a conference organised by Christian Concern and a US conservative group that was set to debate gay marriage at the Law Society's London headquarters

Sir Paul Coleridge, the family division judge who recently launched a new charity to combat marital break-up, was to be among the main speakers, but the event was called off after the Law Society ruled that the programme reflected "an ethos which is opposed to same-sex marriage".

Christian Concern's activities have included helping to organise a 2010 conference where speakers promoted "therapy" for gay and bisexual people and last year was heavily involved in a campaign that led to peers voting by five votes to amend the equality bill, giving faith groups legal opt-outs that effectively allowed them to refuse to employ gay, bisexual and transgender people.

It advertised earlier this month for a communications manager and a fundraising manager who would "develop relationships with churches, major donors and be responsible for developing and promoting individual regular giving and direct marketing activities".

Asked to clarify the nature of its relationship with the Christian Legal Centre, the LCF said: "The LCF is a completely separate organisation from the Christian Legal Centre. It provides no funding and is not involved with it. Our website has links to a number of different organisations. The LCF website makes it clear that it has no control over, and assumes no responsibility for, the content, privacy policies, or practices of any third-party websites for which it has hyperlinks."