David Cameron has pledged to remove the "cloak of secrecy" from government as he sought to move on from David Laws' dramatic resignation.
The Prime Minister promised the public greater access to information including hospital superbug figures, street-by-street crime data, and itemised lists of Whitehall spending.
But the transparency drive was in danger of being undermined by another "old politics" setback with fresh claims in the Daily Telegraph that Mr Laws' successor as Chief Secretary to the Treasury Danny Alexander had dodged capital gains when selling a property he designated to Parliament as his second home.
Aides to the Lib Dem MP insisted he had never "flipped" designations and simply followed tax rules, meaning people are not eligible for CGT if they own two homes, but sell one within three years.
Mr Alexander is said to have owned the south London flat for six years before becoming an MP in 2005, when he told the parliamentary authorities it was his second home. At around the same time he purchased a constituency home in Scotland. According to the Telegraph, he claimed more than £37,000 in expenses on the flat before selling in June 2007.
But because that was still within the three-year period, he was not eligible for CGT. The newspaper said he was likely to have saved thousands of pounds as a result.
"I have always listed London as my second home on the basis set out in the parliamentary rules as I spent more time in my constituency than I did in London," Mr Alexander said in a statement. "I sold the flat in 2007 and moved to another flat but was advised that CGT was not payable because of the operation of final period relief, which exempts homes from CGT for 36 months after they stop being the main home. I paid all the taxes required but CGT was not payable on the disposal of my flat. I have already publicly declared that I will pay capital gains tax if the time comes for me to sell my (new) second home."
The latest row emerged as the dust was still settling after Mr Laws' shock departure, after admitting he had channelled tens of thousands of pounds of public money in rent to his boyfriend.
Conservative Cabinet colleagues including Iain Duncan Smith and Ken Clarke praised the Yeovil MP on Sunday for making the "right" and "honourable" decision to quit. But they also indicated his absence could be short lived.
"I am deeply sorry that he has had to go," Mr Duncan Smith told the BBC's Andrew Marr programme. "I have no questions at all that he has the talent to be back."