The Government is planning to increase significantly the minimum amount that UK nationals must earn before being allowed to bring a dependent foreign spouse to live in Britain.
In a hard line speech on immigration today David Cameron will also announce plans to lengthen the time that couples have to be together before they can settle in this country.
The Prime Minister hopes the measures will reduce the 50,000 visas granted to family members of British citizens every year.
But the move is likely to prove controversial with immigrant groups and could be open to challenge in the courts for discriminating against couples on low incomes.
Mr Cameron is expected to announce the partial results of a government inquiry which found that 70 per cent of UK-based sponsors had post-tax earnings of less than £20,000 a year. He will say that current levels of earning are not enough to ensure that married immigrants will not become dependent on benefits.
"We need to make sure – for their sake as well as ours – that those who come (to Britain)...have the resources they need to live here and make a contribution here – not just to scrape by, or worse, to subsist on benefit.
"When the income level of the sponsor is this low, there is an obvious risk that the migrants and their family will become a significant burden on the welfare system and the taxpayer.
"So we have asked the Migration Advisory Committee to look at the case for increasing the minimum level for appropriate maintenance.
"And we're going to look at further measures to ensure financial independence: discounting promises of support from family and friends, and whether a financial bond would be appropriate in some cases."
In his speech Mr Cameron will also announce new measures to cut back on "sham" marriages. He will cite the case of Pakistani national who applied for a spouse visa on the basis of his marriage to someone settled in the UK. The man obtained indefinite leave to remain but then divorced his UK-based spouse and returned to Pakistan, re-married and then applied for entry clearance for his new spouse.
"We simply cannot sit back and allow the system to be abused in this way," he will say. "So we will make migrants wait longer, to show they are in a genuine relationship before they can get settlement. And we'll also impose stricter, clearer tests on the genuineness of a relationship, including the ability to speak the same language and to know each other's circumstances."
In an attempt to appease the left Mr Cameron will also announce that he intends to look at new measures to crack down on forced marriage – including the possibility of making it a specific offence to force someone to marry. He will describe forced marriage as "little more than slavery" and will say it is an issue that the Government should not shy away from addressing.
"I am also asking the Home Secretary to consult on making forcing someone to marry an offence in its own right."