David Cameron has been accused of a "lazy and misguided" approach after warning that 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.
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".
Mr Cameron faced a backlash from Muslim groups and former Cabinet minister Baroness Warsi for linking the issue of English language skills to extremism.
The Prime Minister 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.
Mr Cameron visited a mosque and a project for Bangladeshi women in Leeds to highlight his new proposals.
Speaking during the visit, the PM said: "The evidence is that there are some 40,000 women in our country who really don't speak any English at all and, perhaps altogether, some 190,000 with very poor English.
"I think it's quite right to say to people who come to our country that there are many rights that you have here - it's a fantastic country to live in - but there are also obligations that we should put on people who come to our country, and chief amongst them should be obligations to learn English because then you can integrate, you can take advantage of the opportunities here and you can help us to build the strong country that we want."
Asked about the threat of deportation, Mr Cameron said: "What we've said is that if people come here on a spousal visa, to be a husband or a wife, we've now said they have to learn English in order to get that visa.
"But after two-and-a-half years, halfway through the programme of getting settlement, they should be improving their English, and if they don't do that then they can't be guaranteed to be able to go to the full stage and retain their visa."
Women arriving in the UK under a spousal visa are currently expected to have English skills at the internationally-recognised A1 beginner level - roughly equivalent to a native-born child starting primary school.
Under the PM's proposal, the women would be expected to have reached the A2 - elementary - level after two-and-a-half years, and B1 - intermediate - after five years.
Lady Warsi, the former Tory chairman who was the first female Muslim Cabinet minister, welcomed the new money for language teaching, claiming it had been a mistake to cut funding for English tuition while she was in government.
But she condemned the way the measure had been announced: "This lazy and misguided linking, and what I saw once again as stereotyping of British Muslim communities, I felt took away from what was a positive announcement."
She told BBC Radio 4's World at One: "My parents came to this country with very little English - my mum's English still isn't great, even though she has been to English language classes.
"They didn't necessarily identify with a Western culture but they absolutely had the right values to bring up five girls, make sure that they were educated and made a contribution to British society.
"So I think it is lazy and sloppy when we start making policies based on stereotypes which do badly stigmatise communities."
She added: "What we should be saying to women is, 'we will give you every opportunity to learn, we will encourage you, support you, that it is a requirement for you to obtain British citizenship'.
"But I think to threaten women and say to them that 'unless you are of X standard we will send you back, even if you have children in the UK who are British and your spouse is British' is, for me, a very unusual way of empowering and emboldening women."
Mohammed Shafiq, chief executive of the Ramadhan Foundation, said: "David Cameron and his Conservative Government are once again using British Muslims as a political football to score cheap points to appear tough.
"There are three million Muslims in this country and the Prime Minister chooses to focus on a very small minority of extremists when clearly the majority of British Muslims reject extremism.
"The Ramadhan Foundation has been clear for many years that we face an increased risk from terrorism and an ideology of hatred.
"The best way to confront it is to build support within Muslims and support the work done across the country, and not lashing out and denigrating Muslims.
"The irony of the Prime Minister calling for more resources to help migrants learn English when his Government cut the funding for English classes in 2011 has not been lost on many people."
Shuja Shafi, secretary general of the Muslim Council of Britain, said: "The Prime Minister is absolutely right in wanting English to be taught more widely.
"Mosques and Muslim civil society would be eager to play their part by hosting English language classes, as many mosques do.
"But the Prime Minister's aim to have English more widely spoken and for better integration falls at the first hurdle if he is to link it to security and single out Muslim women to illustrate his point."
Shadow home secretary Andy Burnham said: "In his desire to grab easy headlines, David Cameron risks doing more harm than good.
"His clumsy and simplistic approach to challenging extremism is unfairly stigmatising a whole community. There is a real danger that it could end up driving further radicalisation, rather than tackling it."