The research was carried out by the British Pregnancy Advisory Service (BPAS) which argues that the finding proves that abortion services are essential if women are to be able to plan their families.

But pro-life groups have condemned the idea that abortion should be seen as a positive choice.

The survey, of more than 2,000 pregnant women seeking abortion, found:

• 38% said they had been using a condom at the time they became pregnant
• 17% had relied on the contraceptive pill
• Just 41% said they had used no method of contraception

Women aged 17 and younger, and those aged 30-34 were most likely to say they had not used a method of contraception.

Almost nine of 10 women claimed that they usually used a method of contraception even if they had not on this occasion.

BPAS chief executive Ian Jones admitted that the numbers who said they used contraception may be higher than those who actually did so, as unprotected sex is frowned on.

But he said: "Even taking this into consideration the survey shows that women have huge problems using contraception.

"It is often assumed that women with unplanned pregnancies have had unprotected sex, but many of our clients say they conceived despite doing their utmost to protect themselves against pregnancy.

"Abortion care is an essential support to other family planning services. Policy makers need to address this and fund abortion services accordingly."

Mr Jones' views were echoed by Toni Belfield, director of information for the Family Planning Association, who said many women suffered tremendous anxiety when seeking an abortion.

She said access to abortion services should be improved, and health professionals should educated to provide a more sympathetic response to women seeking a termination.

She said: "There will always be a need for abortion and choosing abortion needs to be recognised as a responsible and positive choice. It needs to be de-stigmatised."

Ms Belfield said that family planning services had failed to educate women in the effective use of contraception.

She also said the British had a tendency to view sex in an immature fashion which contributed to widespread misconceptions and ignorance about effective family planning.

She said: "The rest of Europe does not deal with sex in same smutty, underhand, schizophrenic way that we do here.

"We have a very, very unhappy way of dealing with sex and that creates embarrassment, it creates stigma, and it means people feel unhappy about going and talking about sex with their doctor."

Pro-life opposition

Paul Tully, general secretary of the Society for the Protection of Unborn Children said it was impossible to de-stigmatise abortion because it involved the killing of an unborn child.

He said: "Choosing abortion is nearly always described by the women who do so as something which they feel is not what they want. Very often it is chosen as a last resort because the women is under enormous pressure, whether that be social, financial or personal."

Mr Tully said that instead of promoting abortion, women should be given help and advice to enable them to feel confident about motherhood.

He also called for education programmes that emphasised the benefits of chastity among the young, rather than the contraceptive choices open to teenagers.

Dr Adrian Rogers, a GP and advisor to the campaigning group Family Focus, said: "The results of this survey prove the stupidity of a society that relies on contraception and abortion, and argues very strongly in favour of protecting children by taking a negative approach to their involvement in sexual activity."