Transport Minister Austin Gatt has declared he will vote against the Divorce Bill in Parliament.
In a letter to The Times today, Dr Gatt writes: "I am against divorce, have voted no and will vote no in Parliament because for me it's a matter of conscience and conscience is not an elastic band that changes with vote levels.
"I have full respect for any other opposite and contradictory position but I cannot see how you can say that in conscience you are against divorce and then vote yes in Parliament!"
Dr Gatt also points out that he had never said that he would resign from Parliament now that divorce had been approved by the referendum.
"I wrote before the meeting of the Party Executive Committee and I said that I would resign from the party (not Parliament) if the party took a position in favour of divorce. Since this did not happen there was never any need for me to resign."
Dr Gatt declared some months ago that he will not be a candidate at the next general election.
His decision to vote against divorce comes a day after staunchly anti-divorce Labour MP Adrian Vassallo said he would vote no, as he had always insisted on doing.
On Monday, Labour MP Carmelo Abela, who had also been against divorce, said he would vote in favour, in line with the referendum results.
Marie-Louise Coleiro Preca, who also campaigned against divorce, said she would abstain. She also announced yesterday that her name would not be on the ballot paper at the next general election.
On Wednesday night, Labour leader Joseph Muscat said MPs should vote yes or, at the very least, abstain from the vote.
Prime Minister Lawrence Gonzi said the will of the people must be reflected in parliament, but MPs should otherwise be free to decide their vote.
Reacting to these developments, a PL spokesman said the Bill would pass thanks to a large majority of Labour MPs who would vote in favour or abstain.
The spokesman said Dr Vassallo's decision to vote no had been announced long ago "and he is ready to shoulder his responsibility".
He also said that Ms Coleiro Preca was a hard-working MP serving the country in the most diligent manner. "She is part of the Labour team and her contribution remains very important. Labour would welcome her candidature if she reconsiders."
Labour's Justyne Caruana and Anton Refalo, who both come from the predominantly anti-divorce district of Gozo, have not declared their vote. Dr Caruana has said she would respect the majority but refused to say whether that means abstaining or voting yes. Dr Refalo has been unreachable for the last couple of days.
Other MPs expected to vote no are Gozo Minister Giovanna Debono, who said she would follow her conscience, and Family Minister Dolores Cristina. Questions sent by The Times to Ms Cristina yesterday were still unanswered at the time of writing.
Meanwhile, a growing number of Nationalist backbenchers who have spoken to The Times want to vote yes but wish to do so with the blessing of their party and, particularly, Prime Minister Lawrence Gonzi. They fear the Cabinet has decided to abstain or vote no, which would make them look disloyal, casting them in a bad light with their anti divorce constituents.
Dr Gonzi says there is nothing wrong in voting no or abstaining in Parliament because that would reflect the division within the country. He recalled it was what the PL had done on EU accession.
But party sources say MPs are unimpressed with this reasoning, questioning whether the PL has become the benchmark for democratic credentials.
Meanwhile, divorce co-sponsor and Labour MP Evarist Bartolo has upped the ante against MPs planning to vote against the will of the majority, suggesting a Maltese version of Egypt's Tahrir Square occupation.
Writing on Facebook, he said Parliament had left this in the hands of voters, so it was unacceptable for any MP, minister or Prime Minister to go against what the public had decided on Saturday.
"If we have people in Parliament who try to belittle the democratic decision we should gather the public in the piazza in front of Parliament and not leave until what has been decided is enacted."
He added: " Are we lesser than those who in the past months took to the streets to make their voices heard on both sides of the Mediterranean, when others tried to silence them?"