A married footballer named on Twitter as having an injunction over an alleged affair with a reality TV star has been identified in Parliament as Ryan Giggs.
Lib Dem MP John Hemming named the Manchester United star during an urgent Commons question on privacy orders.
Using parliamentary privilege to break the court order, he said it would not be practical to imprison the 75,000 Twitter users who had named the player.
The High Court has again ruled that the injunction should not be lifted.
It rejected two attempts on Monday to overturn the ban, the first after a Scottish paper named the footballer on Sunday, and the second after Mr Hemming's action.
The player obtained the order against ex-Big Brother contestant Imogen Thomas, who is a former Miss Wales, and the Sun newspaper.
The footballer's lawyers have also obtained a High Court order asking Twitter to reveal details of users who had revealed his identity after thousands named him.
Parliamentary privilege protects MPs and peers from prosecution for statements made in the House of Commons or House of Lords.
Addressing MPs, Mr Hemming said: "Mr Speaker, with about 75,000 people having named Ryan Giggs it is obviously impracticable to imprison them all."
House of Commons speaker John Bercow interrupted the MP saying: "Let me just say to the honourable gentleman, I know he's already done it, but occasions such as this are occasions for raising the issues of principle involved, not seeking to flout for whatever purpose."
John Hemming later told the BBC why he had named Mr Giggs.
"Basically when he... showed that he was going to go after relatively normal people and try and prosecute them, for gossiping about him on a matter of trivia, I think he has to be held to account for that," he said.
John Whittingdale, Conservative chairman of the Commons culture committee, said he "regretted" Mr Hemming's use of parliamentary privilege to name Mr Giggs.
"Firstly because I think, if MPs think the law is wrong then we should change the law rather then flout the law," he said.
"And secondly because the result of that is that the only thing being reported is the name of Ryan Giggs and we're rather losing sight of the bigger issue, which is how the law of privacy is operating in the UK."
Labour MP Tom Harris said it was "incredibly irresponsible" of Mr Hemming to name the footballer.
"We leave these decisions up to judges who are very careful to look at both sides of the argument, and then suddenly you have a self-publicist like John Hemming," he said.
"There's no justification for it whatever," he added.
"I genuinely believe that people in this country, even multi-millionaires, have got a right to privacy."
Mr Justice Eady said when rejecting a second application - the first of Monday's attempts - by Sun publisher News Group Newspapers to discharge the privacy injunction, that the court's duty "remains to try and protect the claimant, and particularly his family, from intrusion and harassment so long as it can".
The Attorney General Dominic Grieve told the Commons the prime minister had asked for a joint committee of peers and MPs to investigate the use of privacy orders.
David Cameron has written a letter to Mr Whittingdale, recommending the setting up of a new body.
Earlier on Monday, the prime minister told ITV1's Daybreak that banning newspapers from naming such stars while the information was widely available on the internet was both "unsustainable" and "unfair".
In another case brought by a separate footballer, known to the court as TSE, a High Court judge ruled on Monday that comments on Twitter about the private life of a famous person did not mean there should be no injunction preventing newspapers from publishing stories about him.
Midfielder Ryan Giggs, 37, is Manchester United's most senior player, having appeared in 613 games.
He celebrated with the team at Old Trafford on Sunday as they were crowned English league champions for a record 19th time, and is expected to be in the squad to face Barcelona in Saturday's European Champions League final at Wembley.
The player, who made 64 appearances for Wales before retiring from international football in 2007, was awarded an OBE that year.
He was named BBC Sports Personality of the Year in 2009.