Radio advertisements warning men that having sex without consent could lead to a prison sentence have been launched by the Home Office.
The campaign will feature adverts in men's magazines and pub toilets
The campaign, which will also use magazine adverts and posters, aims to reduce the number of sex assaults that occur when a woman is very drunk.
It comes amid low conviction rates for rape cases in England and Wales.
The government may also change the law to allow juries to decide whether a woman was too drunk to give consent.
The £500,000 campaign will be followed on 20 March by adverts in men's magazines, stickers on condom machines and posters in pub toilets.
They will say that unless a woman actively says "yes" to sex then men must assume the answer is "no".
'Onus on men'
Home Office Minister Fiona Mactaggart said she hoped the adverts would encourage women to think that the law was on their side.
"For a long time, work to raise awareness of sexual violence has focused on the need for women to take responsibility for their personal safety," she said.
"That is still important, but I believe that we need to start putting the onus onto men and make them aware of their responsibilities."
Rachel Mostyn of Cosmopolitan Magazine, which in January conducted a survey among its readers on their attitude to rape, said many respondents did not understand "the incredibly complicated consent issue".
"They have been in situations where they're out on a date, they then go back to someone's house for a coffee, things go on and then that person wants to have sex with them.
"They quite clearly say no but that person goes ahead anyway.
"Now, that's sex against their will, but they're still not sure whether that's rape or not."
She said she hoped the campaign would make men "take more responsibility".
Stephen Cooper, a campaigner against wrongful rape conviction, said that "steps should be taken by the man to say 'would you consent to sexual activity later on in the evening'?"
But if a woman was drunk, a man should not consider sleeping with her, he said.
"I think a lady is incapable of giving consent when she is drunk," he added.
According to Home Office figures, only 5.8% of reported rapes in 2004 resulted in a conviction.
Attitudes towards rape have also been highlighted as a problem.
Research by Amnesty International last November found that one third of people in the UK believed a woman was partially or completely to blame for being raped if she had behaved in a flirtatious manner.