A CATHOLIC Mersey MP pledged yesterday to lead a fresh Labour revolt on embryo research and lesbian fertility treatment – despite Gordon Brown’s offer of a limited free vote.

Claire Curtis-Thomas, the Crosby MP, vowed to try to vote down the Human Fertilisation and Embryology Bill at its final Commons stage if its most controversial clauses survive earlier votes.

The threat comes despite the prime minister granting Labour MPs a free vote in three key areas, in a bid to head off a damaging Cabinet split and calm growing anger among church leaders, particularly in the Catholic Church.

They are; using hybrid animal-human embryos for stem cell research, making it easier for single women and lesbian couples to have fertility treatment and creating “saviour siblings” to save a sick brother or sister.

But Mr Brown insisted his MPs would face a three-line whip on the final reading of the Bill – creating a new flashpoint if the “conscience” clauses are passed.

Within hours of the announce-ment, Ms Curtis-Thomas – a practising Catholic – spoke out to insist the concession did not go far enough.

The MP said: “You can’t say ‘I don’t agree with this, therefore I am seeking to have an opt-out from this particular clause but, by the way, if the vote is lost and comes back, I will vote for it’.

“For some individuals, including myself, this is primarily a moral question and, at end of day, I have to answer to my conscience. At whatever stage this arises, I will not be able to agree with it.”

If Ms Curtis-Thomas does rebel, she will be forced to resign her position as unpaid parliamentary aide to attorney general Baroness Scotland, the first rung on the ministerial ladder.

Two other local Catholic MPs who have pressed for a free vote are in a similar awkward posi-tion as unpaid aides – Rosie Cooper (West Lancashire) and Helen Jones (Warrington North).

The region’s other three Catholic MPs are Joe Benton (Bootle), Peter Kilfoyle (Liver- pool Walton) and Helen South- worth (Warrington South).

ROB MERRICK: PAGE 11