Muslim women who fail to improve their English language skills could be deported as part of a drive to build community integration and counter extremism, David Cameron has said.

The Prime Minister warned that not speaking the language adequately could make people "more susceptible" to the recruitment messages of groups like the self-styled Islamic State (IS) - though there was no "causal link".

And he said it was "not acceptable" that women in parts of the UK were not allowed to leave their homes without a male relative and faced sex-segregated school governors meetings.

A £20 million language fund is being set up to help end what he called the "passive tolerance" of separate communities which left many Muslim women facing discrimination and social isolation.

Women who come to the UK to join husbands will face tests after two and a half years - with failure meaning "they can't guarantee they will be able to stay" even if they have children, Mr Cameron told the BBC Radio 4 Today programme.

"You have to be able to speak a basic level of English now to come into the country as a husband or a wife.

"We have made that change already and we are now going to toughen that up so halfway through the five-year spousal settlement programme, there will be another opportunity to make sure your English is improving.

"You can't guarantee you will be able to stay if you are not improving your language.

"It is tough. But in the end it is not enough just to say the Government is going to spend more money and it is our responsibility. People coming to our country, they have responsibilities too."

He said: "I am not blaming the people who can't speak English. Some of these people have come to our country from quite patriarchal societies where perhaps the menfolk haven't wanted them to learn English, haven't wanted them to integrate.

"Where there is segregation, it is holding people back, it is not in tune with British values and it needs to go. We need to be more assertive."

The Government estimates that there are 190,000 Muslim women in England who speak little or no English.

Mr Cameron told Today: "The reason for doing this is to build a more integrated country, to build a One Nation Britain, to give people more opportunities.

"But I think there is a connection with combating extremism and it is this: if you have people growing up in a house where no-one speaks English, they are less able to talk to the school, less able to communicate with a local GP.

"I am not saying there is some sort of causal connection between not speaking English and becoming an extremist, of course not. That would be a ridiculous thing to say.

"But if you are not able to speak English, not able to integrate, you may find therefore you have challenges understanding what your identity is and therefore you could be more susceptible to the extremist message."

He defended previous cuts to language funding which critics say have undermined integration efforts.

"We had to make difficult decisions. Now what we are doing is targeting the language money much more accurately.

"It is just for women, not necessarily just for Muslim women - it is for those in the greatest danger of isolation."

And he rejected the idea of banning full-face veils as part of the policy.

"In our country people should be free to wear what they like," he said.

"When you are coming into contact either with different institutions or, for instance, you are in court or you need to see someone's face at the border then I would always back the authorities or the institutions that have put in place proper and sensible rules.

"Going for the French approach of banning an item of clothing, I do not think that's the way we do things in this country and I do not think that would help."

Writing in The Times, the Prime Minister said he would not avoid telling the "hard truths" required to confront the minority of Muslim men whose "backward attitudes" led them to exert "damaging control" over women in their families.