MPs are to investigate Prince Charles's controversial veto over Government legislation that affects Duchy of Cornwall interests.
It has emerged ministers have been forced to seek permission from the heir to the throne to pass at least a dozen Government bills, including on laws from road safety to gambling and the London Olympics
The Duchy of Cornwall is a £762 million estate of about 131,000 acres, including extensive property in Cornwall itself and large landholdings mostly in the South West – including a third of Dartmoor and its moorland prison and swathes of the Isles of Scilly.
The royal veto, which critics say influences ministers if not used, will be examined by the House of Commons political and constitutional reform committee next month. Labour MP Graham Allen, chairman of the committee, will ask whether there is a risk that the requirement "could be seen as politicising the monarchy".
The questions being asked by the committee, whose members include the historian Tristram Hunt, include: "Is there a continuing justification for the Queen's or prince's consent to be part of the legislative process?"
Mr Allan said seeking Charles's consent to laws that affect his interests was "a relic" but stressed his focus was on how the executive may manipulate the royal prerogative to push through decisions without the proper scrutiny of MPs.
No members of the royal family or their staff are expected to be called to the three hearings scheduled for September, Mr Allan said.
Both Clarence House and Buckingham Palace said it was "a long-established convention" that the prince, as Duke of Cornwall, is asked by parliament to provide consent to those bills that Parliament has decided would affect Duchy of Cornwall interests.
They said the same process is followed with regards to the Queen providing consent to bills that would affect Crown interests.
This week, it has emerged that Charles has held 36 meetings with ministers since the government took power in May 2010. He has met the prime minister, David Cameron, seven times, four different ministers in the Department for Communities and Local Government and held six meetings with ministers in the Department of Energy and Climate Change.
Last month MPs quizzed the Prince's key aide over the Duchy of Cornwall's tax arrangements.