MPs are awaiting the report from Sir Christopher Kelly on their parliamentary allowances – due to be published tomorrow. Leaked details indicate Sir Christopher is to withdraw several expenses including mortgage interest payments for second homes, forcing MPs to rent accommodation. In addition, the employment of family members at the taxpayers’ expense is expected to be banned.

Although his official spokesman refused to comment on the details of discussions with Sir Christopher, the Prime Minister has already made it clear that the reform of expenses, following the summer scandal, should not end up deterring ordinary people from entering politics.

He told a Speaker’s conference on political representation recently that it was important for the Kelly reforms not to send a message that only rich people could enter Westminster.

Mr Brown’s meeting with Sir Christopher, the chairman of the Committee on Standards in Public Life, was described as a “routine briefing”. Tory leader David Cameron and the Liberal Democrats’ Nick Clegg held similar talks with the standards chief last week.

In advance of the meeting, a Downing Street source said Mr Brown would say that “ordinary people with families must always be able to become MPs”.

“The vast majority of MPs work extremely hard. Most are in it for what they can give, not what they can get.

“He feels MPs have been let down by a bad system and some bad apples.”

While Mr Kelly is expected to recommend huge cuts in MPs’ expenses it is reported that several submissions to his inquiry have urged a substantial increase in parliamentary salaries to offset the losses.

Such an explosive recommendation would be bound to inflame media and public anger with MPs whose expenses over the last five years were released following a Freedom of Information campaign that exposed several abuses of the system.

The Kelly Report will be unveiled in an oral statement to MPs by Leader of the Commons Harriet Harman tomorrow, and will then be implemented by the new Independent Parliamentary Standards Authority.

No Commons vote will be required to approve the report, but the IPSA will be required to consult on Kelly’s findings and may be able to “shape” his recommendations in the process of implementing them, said the Prime Minister’s spokesman.

The IPSA has been legally established but currently has no chairman or board and Mr Brown’s spokesman was unable to say exactly when it will be in a position to begin its work, though he said it would be “a matter of urgency”.