The Illegal Migration Bill has cleared its first reading in the Commons, although some Conservative MPs have called for amendments to protect trafficked women, children and modern slavery victims.
The controversial asylum proposals aim to stop people claiming asylum in the UK if they arrive through unauthorised means, although it has been denounced by the UN’s refugee agency as an “asylum ban”.
The House of Commons voted 312 to 250 to give the Bill a second reading.
Home Secretary Suella Braverman said the legislation was needed as people arriving in the UK after crossing the English Channel have “overwhelmed our asylum system”.
Ms Braverman said there had been “too much” immigration in recent years.
She said she had been subjected to the “most grotesque slurs” for saying “simple truths” about the effects of migration on the country.
But Conservative former prime minister Theresa May warned that modern slavery victims will be “collateral damage” and have the door shut on them by measures within the Bill.
Mrs May said she was expecting to hold further talks with Downing Street to resolve the issues and noted how, when home secretary, she took action to respond to people jumping in the backs of lorries and cars to get into the UK.
“But what should be clear from this is whenever you close a route, the migrants and the people smugglers find another way, and anybody who thinks that this Bill will deal with the issue of illegal migration once and for all is wrong," she said.
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The Bill would enable powers to detain migrants for 28 days without recourse for bail or judicial review, and then indefinitely for as long as there is a “reasonable prospect” of removal.
Challenges based on modern slavery laws would be barred, and any other legal attempt to stay would be heard overseas — after the migrants are removed.
Labour former minister George Howarth said the situation for asylum seekers in Knowsley has “deteriorated” since a protest outside their hotel, with some being assaulted.
In a protest last month outside a hotel housing asylum seekers in Knowsley, Merseyside, a police van was vandalised and fireworks thrown.
Mr Howarth said “we should all be ashamed” of the situation, as he hit out at the government’s Illegal Migration Bill in the Commons.
“I want to agree with the Home Secretary on one thing. And that is when she said we should choose our words carefully. It’s just a pity she didn’t do so herself," he said.
“There is a hotel in Knowsley with 180-plus asylum seekers. I won’t talk about that in detail because I had an urgent question on it a few weeks ago.
“But what I will say is since then the situation has deteriorated to the extent that some of the refugees have been verbally abused in the street, and others have been assaulted.
“And they have fled because the countries they come from were unsafe, only to find themselves in an unsafe position in this country. And I think we should all be ashamed.
“It’s not just happening in Knowsley, it’s happening all over the country.”
Conservative former justice secretary Robert Buckland warned that the tone of some in his own party is “not appropriate” and said there was a danger of “ineffective authoritarianism” from parts of the Bill.
Mr Buckland expressed “great concern” at the prospect of detaining children.
Shadow home secretary Yvette Cooper, writing on Twitter, said: “The Tories' Migration Bill is a con that will make chaos worse.”
But Conservative former minister John Hayes told the Commons: “Of course Britain should provide a safe haven for people in need, in genuine need.
"But it is a deceit to pretend the asylum system is not being gamed and the British people taken for a ride.”
There were heated exchanges involving both sides of the Commons, with some heckled for their language.
Green Party MP Caroline Lucas criticised the “immoral, deeply cruel and divisive” proposal, and ripped up a copy of the Bill at the end of her speech.
Conservative MP Marco Longhi, a member of the home affairs committee, said people were travelling from “the other side of Africa or from other godforsaken country all the way to Calais”.
Labour tabled an amendment that sought to block the Bill but it was defeated by 249 votes to 312.
After the votes, Ms Braverman said in a statement: “Tonight’s vote proves what we already knew — the Labour Party cannot be trusted to stop the boats and the gangs that profit.
“Labour not only has no plan to stop the boats, they have no desire to either.”