Tessa Jowell was greeted by cheers from Labour MPs as she made her first Commons appearance following claims about her husband's financial dealings.
Tessa Jowell laughed and smiled during her Commons appearance
The culture secretary smiled during the session, which comes days after she separated from her husband David Mills.
She has met the standards watchdog to see if she needs to amend her entry in the MPs register of interests. He has concluded she does not.
Tony Blair has backed Ms Jowell saying she is doing "an excellent job".
He gave his support as Environment Secretary Margaret Beckett urged Ms Jowell to "tough it out", claiming she was facing "trial by ordeal".
Ms Jowell was surrounded by Cabinet ministers, including Health Secretary Patricia Hewitt and Education Secretary Ruth Kelly, as she rose from her seat to answer a question in the Commons about the switchover to digital television.
To Labour cheers she joked: "I hope my departmental questions continue to provide the political highlight of the month."
Tory shadow culture secretary Hugo Swire told Ms Jowell that while he understood this "must be a difficult personal time for you, we must not allow recent events to interfere with the running of your department".
Earlier, Mr Mills, who is being investigated by Italian prosecutors but who denies any wrongdoing, said he was disgusted by claims his split with Ms Jowell was a sham.
He told the Times newspaper: "The idea that people could decide on a separation for contrived reasons - it's just not how human beings behave."
He said they had a "long and happy" marriage behind them and he hoped there would eventually be a reconciliation.
Mr Blair, speaking at a press conference with Pakistan Prime Minister Shaukat Aziz, said he believed Ms Jowell was doing "an excellent job and should be allowed to get on doing it".
His official spokesman said the marriage split was "purely a personal matter".
"Everybody recognises this is a difficult time, but Tessa Jowell continues to enjoy the prime minister's full support and she should be allowed to get on with her job," he said.
Mr Mills, an international lawyer, has denied any wrongdoing
Mrs Beckett said Ms Jowell was "one of the most popular" people in the Commons, who has "always been regarded by everybody as having integrity".
She said Ms Jowell must be "absolutely devastated" by the break up of her marriage and described suggestions that the split might be a ploy to save her career as "distasteful in the extreme".
"If she can possibly stand it - she should tough it out because it's just awful," she told BBC Radio 4's Today programme.
"There is nothing said yet that's been shown to be illegal. Nothing that Tessa's done shown to be illegal," argued Mrs Beckett.
"It's a kind of witch-hunt and it really ought not to go on."
Mr Mills' lawyer has blamed the marriage break-up on a row over a £344,000 Italian payment.
Earlier in the week, Ms Jowell, 58, was cleared of breaching the ministers' code of conduct - because a report said her husband had not told her about a £344,000 gift he had received.
Italian prosecutors have been examining claims the money was paid to Mr Mills, an international lawyer, in return for helpful testimony in a corruption probe concerning Italian prime minister Silvio Berlusconi in 1997.
And The Observer newspaper claimed Mr Mills allegedly made a £67,000 profit on shares he bought in the Old Monk Company pub chain in 1998, when Ms Jowell was a public health minister.
Conservative leader David Cameron expressed his sympathy that Ms Jowell's marriage had broken down, but added that there were still unanswered questions about the couple's finances.
"There needs to be a better way of judging how ministers have abided by the ministerial code," he added.
Tory MP Nigel Evans, a member of the Commons Culture, Media and Sport committee, hand-delivered a letter to Ms Jowell to press her further about her finances.
A spokesman for her department said she would be replying to that letter now Sir Philip Mawer, the parliamentary commissioner for standards, has told her she does not need to change her Register of MPs' Interests entry.
Ex-Sports Minister Kate Hoey said Ms Jowell's personal problems would be a distraction to the London election campaign and urged her to make a statement.
However, Labour MP Bob Marshall-Andrews, often a thorn in the side of the government, said he did not think Ms Jowell should go.
The way prosecution evidence appeared to be leaked to the media was unfair and should not decide the fate of a minister, he said.
Both Mr Mills, 61, and Ms Jowell have denied any wrongdoing.