Forty women from the North will this week travel to Westminster to urge British MPs to support legislation to make abortion available in Northern Ireland.

An amendment to the Human Fertilisation and Embryology Bill, which has been tabled by Labour MP Diane Abbott, is due to be debated in the House of Commons later this month. It proposes that the 1967 British Abortion Act be extended to the North. Such legislation would also mean Southern women could cross the Border to have abortions. The North's four main political parties have all written to MPs to oppose any change in the law and claim they have the support of 90% of the population.

The 40 women represent the 40 women a week who currently travel from the North to Britain and Europe to have abortions. A letter signed by prominent individuals in the public, legal, academic and community sectors also urges MPs to extend the 1967 Act.

Among the signatories are Irish Congress of Trade Unions president Patricia McKeown; former Westminster MP Bernadette McAliskey; Annie Campbell, director of Northern Ireland Women's Aid; Audrey Simpson, director of the North's Family Planning Association and Eileen Calder of Belfast Rape Crisis Centre.

Alliance Assembly member Anna Lo, Progressive Unionist leader Dawn Purvis, and Baroness May Blood of the Shankill are also supporting the women. Goretti Horgan of Alliance for Choice said: "We totally reject the claim by the four main parties that 90% of people in the North oppose abortion. We challenge them to hold a referendum on the issue. But regardless of what the DUP, Sinn Féin, the SDLP and Ulster Unionists say, women will continue to vote with their feet and travel to Britain or Europe for abortions. Almost 80,000 have gone since 1967.

"Women should not be forced to make such expensive and often emotional journeys. Working-class women often struggle to raise the £1,000 it generally costs in travel and medical expenses."

Gordon Brown is rumoured to have done a deal with the DUP whereby they supported the 42-day detention of terrorist suspects in return for Westminster leaving it to the Stormont Assembly to legislate on abortion.

"That's like saying 'leave it to the Taliban to sort out women's rights'. It's also double standards because abortion has not been devolved to the Scottish or Welsh administrations," Horgan said.