Jeremy Hunt, the embattled Culture Secretary, faced fresh pressure last night after it emerged he failed to declare business donations worth more than £7,000.
Labour has called for him to be sacked after it emerged that his adviser, Adam Smith, had been in constant contact with News Corporation while the minister was considering its bid for BSkyB.
Mr Hunt, who has denied any wrongdoing, is due to give evidence to the Leveson Inquiry this month.
Last night there were calls for the Culture Secretary to be investigated by the Commons watchdog over his failure to declare three Tory "networking" events before the 2010 general election when he was the shadow Culture Secretary. One gathering was funded by the advertising giant M&C Saatchi to the tune of £4,563.
The advertising agency DDB UK funded an event worth £1,474, while a third worth £1,435 was paid for by the Groucho Club.
However, the details of the three events were not lodged with the Commons register of interests.
Mr Hunt's deputy, Ed Vaizey, stated in his register entry that they were both at eight separate events sponsored by private companies between July 2009 and March 2010.
He said the functions were to "enable the Conservative frontbench team to meet sector leaders from the arts and creative industries". They included one – registered by Mr Hunt – hosted by BSkyB on 7 October 2009, which cost £3,800.