British lawmakers pushed a bill against renting to illegal immigrants over its first parliamentary hurdle on Tuesday, amid warnings of a possible rise in discrimination as the government hardens its rhetoric.

The proposed law is at the heart of the push by Prime Minister David Cameron’s centre-right Conservatives to create a “hostile environment” for people not authorised to be in the country.

Under the proposed measures, British landlords could be jailed for up to five years if they rent property to people they know or have reasonable grounds to suspect of being illegal immigrants.

Other measures include potential six-month jail terms for people who work illegally, allowing police to seize their wages as “proceeds of crime” and making it a legal requirement for certain public sector workers to speak fluent English.

The Immigration Bill cleared its first stage in the lower house of parliament on Tuesday, after 323 lawmakers voted in favour while 274 voted against.

It will now go to further debate and could take months to pass through parliament before becoming law.

The bill has been criticised by opposition parties and campaigners, who say it could increase discrimination against all people from ethnic minorities, including those in Britain legally.

It also drew questioning from within the ruling Conservative party, with lawmaker Richard Fuller stating during the debate that “it is very difficult for someone to see if someone is an illegal immigrant, what they see is someone who is different”.

“Do you not accept that within this law there is the potential for discrimination to be increased if this is pursued too aggressively?” Fuller asked.

– ‘Fear and hostility’ –

In response, Home Secretary Theresa May said that too-high immigration put pressure on housing and public services and said it was important that it be “properly managed”.

“It is only fair to people who are coming here… who have actually played by the rules, that we do take efforts to ensure that those who are here with no right to be here who are abusing our systems are actually dealt with appropriately,” May told parliament.

May drew criticism for a speech this month in which she said too high immigration made a “cohesive society” impossible, seen as a bid to position herself as a potential right-wing future candidate for the Conservative leadership.

Cameron’s party secured a surprise victory in May’s general election with a manifesto which made reducing immigration one of its central themes.

Net migration to Britain was estimated at 330,000 in the year to March — the highest figure on record — and the Conservatives want to cut this to tens of thousands annually.

The main opposition Labour party, led by left-winger Jeremy Corbyn, says the bill could signal the return of the kind of discrimination faced by immigrants to Britain in the 1960s when they sought accommodation.

“The new document checks could become the modern equivalent of the ‘no dogs, no blacks, no Irish’ signs,” Labour’s home affairs spokesman Andy Burnham wrote in this week’s Independent on Sunday newspaper.

The Joint Council for the Welfare of Immigrants campaign group said the measures would increase “the fear and hostility felt by those who appear different,” who would “find it more difficult to live in the UK”.