Prime Minister David Cameron will set out further plans to curb benefits to migrants this week, in an attempt to see off the threat posed by the insurgent UK Independence Party, who won their second MP on Thursday night. His party is said to be in disarray over the issue of immigration, with reports of infighting during a meeting of backbenchers this week.

According to the Sunday Times, Cameron and his aides have been drawing up proposals based on suggesting by the think tank Open Europe, which would see newly arrived migrants barred from claiming in-work benefits such as tax credits, housing benefit and social housing, for at least two years.

A report by Open Europe, due to be released tomorrow, will make the case that many EU migrants currently find even minimum wage jobs lucrative thanks to in-work benefits. Cutting those benefits would therefore make migration to Britain a less attractive proposition.

For example, a Spanish worker on minimum wage sees their pay packet rise from £214.07 in Spain to £290.28 in the UK, a gain of £76.21 a week. Cutting in-work benefits would mean that they would receive £196.51 a week, and be £17.56 a week worse off than they were in Spain.

There has been no official word from Cameron’s team at 10 Downing Street, but senior Conservative backbencher John Redwood said “I want Britain to take back control of its own borders and welfare system and the best way would be by agreement with our European partners and by clarificatory legislation in the UK, to amend the 1972 European Communities Act.

“It would concentrate the minds of people on the continent wonderfully. That is what I would want him to set out in his speech.”

Immigration policy is becoming an internal battleground within the Conservative party, with the Mail on Sunday reporting that the Parliamentary party went into “meltdown” over the issue at an “immigration summit” held in Westminster. There were angry clashes between Members of Parliament who want to see their leaders go further in curbing immigration, and those who believe higher immigration is a boost to the economy.

Former cabinet minister Peter Lilley is said to have demanded an “emergency brake” on EU migrants entering the country, saying “Most people believe Britain is full – and they are right. We are already a nation of more than 60 million. We cannot take any more and have to shut the door.”

Jake Berry, a Lancashire MP backed Lilley, saying that Cameron must not be “outflanked” by Labour Leader Ed Miliband, who earlier this week announced that, under Labour’s plans, migrants would not be able to claim unemployment pay-outs for two years.

But they were opposed by Margot James MP, who praised “hard-working Poles and Bulgarians,” warning that the Tories “must not dance to Ukip’s tune”. Reading a pre-prepared statement, she argued “There is a danger that the anti-immigration and anti-EU minority tail is wagging the majority British dog. There is a clear case that needs to be made for immigration. Their role in wealth creation should not be underestimated.

“The day people are put off by the constant negative rhetoric about people coming to this country, and stop coming, is the day we will have far more to worry about.”

Jo Johnson MP, brother of London Mayor Boris Johnson also said that fears over immigration were unfounded, reportedly saying “95 percent of Britain is undeveloped”. A fellow MP told the Mail “It sounded as though Johnson was saying there is plenty of room for more immigrants.”

And Daniel Korski, Cameron’s immigration special adviser who has previously worked for Baroness Cathy Ashton, the former EU High Commissioner, dismissed Lilley as “shrill”.

“It was pretty lively. It was Jo, Margot and Korski versus Lilley and the rest,” said one source. Another said “Jo Johnson and Korski are part of the cosy Downing St chumocracy. They just don’t get ordinary people’s concerns about immigration.”

Immigration as an issue shows no signs of going away, as a new report by the Social Security Advisory Council for the government has warned that Britain faces rising immigration as her economy improves, and that retracting benefits was likely to cause an “almost inevitable” rise in social problems, such as rough sleeping, crime and rising costs to the NHS, the Telegraph has reported.

“The fact that the UK’s economy is seen to be in a healthy state of recovery compared to many other EU member states would mean that more [European] nationals will arrive in the months to come, rather than less,” the report states.

It argues that the rising number of migrants flocking to the UK  was “more closely related to the state of the economy” and their ability to “find work quickly” than the attraction of benefits. In a letter to Work and Pensions Secretary Iain Duncan Smith, Paul Gray, the chairman of the SSAC wrote “If you do have the relative strength of our economy compared to others, that’s likely to be the dominant impact on the flows, rather than shifts in restrictions on benefit.”

He also said that it was “fairly likely” that taking away housing benefit and other in-work benefits would mean workers sending money back to their home countries, rather than bringing their families with them.