Cameron facing probe amid calls for him to resign
British Prime Minister David Cameron is now facing an inquiry by the parliamentary standards watchdog into the failure to declare his stake in an offshore trust after a Labour MP pledged to submit a complaint.
John Mann, the MP for Bassetlaw, said he would refer the prime minister to the Parliamentary Standards commissioner over whether he had breached the code of conduct.
In the rules, it says MPs should "be open and frank in drawing attention to any relevant interest" they may have while serving.
Mr Cameron appears not to have alerted the House of Commons to the fact that he had a stake in an offshore fund until January 2010, when he sold up.
Mr Mann said: "David Cameron has broken the rules on Standards in Public Life that he, along with me and others, voted for.
"No interpretation of his actions could conclude that he has acted in an 'open and frank' way, in line with the Code of Conduct for MPs.
"It is only now, with the Panama revelations, that David Cameron has been forced to admit that he did not register his financial interests.
"This is a matter of transparency and integrity. David Cameron has shown neither of these qualities and should resign as prime minister."
Mr Mann's office cited a part of the code of conduct: "Members shall fulfil conscientiously the requirements of the House in respect of the registration of interests in the Register of Members' Financial Interests. They shall always be open and frank in drawing attention to any relevant interest in any proceeding of the House or its Committees, and in any communications with Ministers, Members, public officials or public office holders."
As the pressure rose on Mr Cameron over the revelations, Ken Livingstone, the former Mayor of London, told the TV channel RT that David Cameron should face a term behind bars.
"I think it is incredibly damaging. All this started with Mrs Thatcher. She stopped all the regulation; people were allowed to move their money abroad, start not paying their taxes. And Cameron's father just spent 30 years laundering money through Panama and did not pay a penny of tax to Britain. And then his son was in denial, refusing to be honest about all of this.
"But, also, it's the hypocrisy. Four years ago during the mayoral election, he was accusing me of tax avoidance.
In fact, I had overpaid tax, and he knew full well that if you want to do tax avoidance you launder your money abroad, as his father was doing. So I do think Cameron is the most hypocritical prime minister of my lifetime."
Asked if Mr Cameron should resign, Mr Livingstone added: "I think he should have resigned right when he started his term of office. It has been the most damaging government.
"Huge damage to the poorest people, to communities that desperately need investment and so on.
"Cameron's government for the last six years has been about a small elite getting richer whilst the poorer get left behind. He shouldn't just resign. He should be sent to prison."
The issue - which has ensnared scores of leaders, stars and others since Sunday's unprecedented leak of 11.5 million documents from clients of law firm Mossack Fonseca - is causing particular damage to Cameron, who for years has campaigned prominently for a crackdown on global tax avoidance.
After three days of obfuscating statements, Mr Cameron admitted on Thursday night he had sold more than £30,000 (about €37,000) in shares in his late father's Blairmore Holdings, an investment vehicle that Mossack Fonseca helped organize in the Bahamas.
Cameron said he bought the shares in 1997, the year his Conservative Party was ousted from power, and sold them in 2010 shortly before his party returned to office with him in the top post.
Tom Watson, deputy leader of the Labour Party, said nobody believed this was Cameron's only involvement in profiting from offshore investments.
Mr Cameron's approval rating has fallen below Jeremy Corbyn's for the first time, a new poll has revealed.
Just 34pc of voters said the he was doing a good job, while 58 pc felt he was not.
The 24 percentage point difference is slightly worse than the 22-point difference between the 30pc who approve of the job Mr Corbyn is doing and the 52pc who disapprove of the Labour leader.
Meanwhile, China's Foreign Minister Wang Yi has strongly denounced accusations arising from the release of the Panama Papers as groundless after their leak this week revealed offshore companies linked to the relatives of Chinese President Xi Jinping and other powerful current and former Chinese leaders.