The Sun newspaper is implicated in the phone hacking scandal and needs to answer some tough questions, Labour MP Tom Watson has alleged.

Watson (pictured) made the claims at the Labour party conference this morning, during an emergency motion debate on phone hacking. Those at the debate called for James Murdoch to stand down as chairman of BSkyB and demanded greater measures to regulate media companies and journalists.

The MP told Labour activists that phone hacking was potentially not limited to the now defunct News of the World.

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He said: "Do you really think that hacking only happened on the News of the World? Ask Dominic Mohan, the current editor of The Sun. He used to joke about lax security at Vodafone when he attended celebrity parties. Ask the editor of the Sun if he thinks Rupert Murdoch's contagion has spread to other newspapers."

Watson added: "If [Mohan] gives you an honest answer, he'll tell you it's only a matter of time before we find the Sun in the evidence file of the convicted private investigator that hacked Milly Dowler's phone."

He then seemed to cite the Times as another paper that has possibly been involved in illegal practices, telling those assembled: "The paper is shutting down its BlackBerry phone network – I hope they aren't deleting the records."

Watson received a standing ovation from delegates for his continued questioning around phone hacking.