The review, under all tiers of the points-based system, is limited to those who unsuccessfully applied for entry from outside Britain between June 23 and July 22 this year.

The review will include cases of those seeking extension from inside Britain (at a time when they had lawful status in this country) on or before July 22.

The review was announced after the high court ruled in an immigration case that the maintenance funds assessment must be made in line with the immigration rules.

The immigration rules only specify that the migrant must hold the required level of funds on the day the application was made.

The immigration case, called the Pankina case, drew the court's attention to the time period for which an applicant should show as having adequate funds for self and any dependents.

Hitherto, separately from the rules, the UKBA had issued guidelines which stated that applicants had to show evidence of cash funds, in the form of personal bank or building society statements covering a period of three months, dated no more than one month prior to the date of submitting the application.

It was also necessary that the balance should not fall below the required minimum at any time during the three month period.

This condition proved difficult to meet for many applicants as they had to show a balance of anywhere between £3,000 and £5,600 in their bank accounts continuously for a period of three months.

The court ruling means UKBA's policy guidelines have to be incorporated into the immigration rules for them to be binding.