Maria Miller leaves 10 Downing Street after a cabinet meeting in London on April 8, 2014. Picture: Paul Hackett

London -

British Prime Minister David Cameron was facing questions over his judgment and leadership on Thursday after one of his cabinet ministers resigned in an expenses row, despite his best efforts to keep her.

Culture Minister Maria Miller, a member of Cameron's Conservative party, resigned on Wednesday after coming under intense pressure for overclaiming parliamentary allowances for a mortgage on her London home.

The prime minister had offered Miller his strong support as she was condemned by newspapers and the opposition Labour party over the course of almost a week.

But the row threatened to re-open the hugely damaging issue of expenses, which caused a major scandal in 2009, and several of Miller's Tory colleagues had openly called on her to step down.

After she resigned, Cameron insisted he was right to defend her while acknowledging the “raw” public anger that remained about the expenses issue, which led to seven lawmakers being sent to jail for fraud.

At a meeting of senior Tory lawmakers on Wednesday evening, the mood was reportedly one of relief that the issue was resolved before the final stretch of campaigning begins for next month's European and local elections.

However, a new ComRes survey found 63 percent thought Cameron had handled the issue badly, and many newspapers reported on how the row had damaged the prime minister's leadership.

“Cameron left fighting for authority,” said the Financial Times online, while The Times reported that the premier had been forced to sacrifice Miller after protests by his close aide and finance minister, George Osborne.

In the House of Commons on Wednesday, Labour leader Ed Miliband accused the prime minister of a “terrible error of judgment” in supporting Miller.

Cameron responded that while she had been censured by the Commons standards committee, it had cleared her of the more serious charge that she had funded a home for her parents at taxpayers' expense.

“I thought it was right, in those circumstances, to allow her to make her apology and continue with her job,” he said.

As culture minister, Miller oversaw the ongoing negotiations on creating a new system of press regulation, following a damning public inquiry sparked by the phone-hacking row.

There have been suggestions that she was a victim of a media witch-hunt, but when asked, Miller said: “I fully accept the findings of the parliamentary report. This is about that.”

She also steered through the legalisation of gay marriage, a policy strongly opposed by many Tories, and some of her allies implied this made her a target.

Critics claim, however, that Cameron and Miller simply failed to realise the public anger about MPs who appear to be abusing their parliamentary expenses.

The prime minister acknowledged on Wednesday: “The biggest lesson I learned (is) that that anger is still very raw and it needs to be acted on.”

Miller's expenses related to mortgage payments she claimed before a new, tighter system of expenses was introduced in the wake of the 2009 scandal.

There are now calls for further reform, after her case revealed how lawmakers are still able to judge for themselves whether MPs have broken the rules.

The independent parliamentary commissioner for standards found Miller should pay back £45 000 that she overclaimed, but that was cut to £5 800 by a committee of lawmakers.

More than 185 000 people had signed an online petition calling for Miller to pay back the larger sum or resign.

A poll published on Tuesday had also found that two-thirds of Conservative Party members thought she should stand down.

In a sign of the mood in the party, Conservative vice-chairman Michael Fabricant responded to Miller's resignation with a Tweet saying: “Well, about time”.

Already an outspoken critic of the government's proposed new high-speed rail project, Fabricant was subsequently sacked.

Miller was replaced by Sajid Javid, a rising star of the Tory party who becomes the first Asian man to sit in the cabinet. - Sapa-AFP