But researchers in Israel have finally been able to create a oral pillthatdeactivates sperm before they reach the womb. And theyve developed a version that means it only needs to be to betaken onceevery three months.

The breakthrough pill could be available in as little as three years,according to the scientist behind the discovery.

Unlike the jab form of the male pill it doesnt use a combination of themalehormone testosterone and the female hormone progesterone to blockpregnancy.

The scientist behind the male pill discovery has developed a tablet thatremoves a vital protein in sperm that is required for a woman toconceive.

So while sperm still get through to the uterus they are unable tofertilise anegg.

Using this approach, researchers believe they have a pill that is 100 pceffective at stopping pregnancy.

Not only is it long lasting but it also has other pluses. There are nosideeffects as suffered by women who take the contraceptive pill.

Men on the male equivalent hormone jabs, which are still undergoingtrialsreport feelings of moodiness, depression and loss of sex drive.

Professor of Haim Breitbart of Israel's Bar-Ilan University, who hashelpeddevelop the pill said: Men dont cope well with side effects and havingsideeffects would probably put many off wanting to take a pill. Weve hadnone ofthose problems with our pill.

What we found is that by treating the mice with our molecule we can getsterility for a long period of time -in the lower dose, about onemonth, andin the higher dose we found three months of sterility.

The mice behaved nicely, They ate and had sex. All I can say is that wecouldn't see any behavioural side-effects - all their sex behaviourwasretained, which is a very important consideration for men. Humantrials ofthe pill are due to start next year.

A big drawback against men being in control of fertility is the feartheywould forget to take a pill.

Polls have repeatedly shown wives and partners do not trust their men toremember to pop a pill every day.

But now that problem has been solved. The new pill can be taken eitheronce amonth or once every three months.

Professor Breitbart said: "I think most women would trust their man toremember once a month or once a quarter.

Breitbarts pill jams the sperm's chemical machinery that allows it tocreate apregnancy. So while the sperm reaches the womb it dies away unable tofertilise the egg.

He said: We looked at a number of compounds that have no effect on malesexdrive, but succeed in impairing the reproductive ability of the sperm.

Because there are no hormonal side effect we believe that it will befairlyeasy to get approval for this pill.

Professor Breitbat stunned the world of fertility science four years agobyrevealing the commonly held belief that conception was immediate oncespermentered the womb.

The research showed that sperm could surive for up to three days beforefertilisation took place.

Professor Breitbart said: I then decided to turn my interest to see howtostop that process. I wanted to develop a form of male contraceptionthatwould be free of an intervention using hormpones.