By Sasjkia Otto
David Cameron's pledge to ignore rules allowing Gordon Brown to hold onto power for an extra week after a defeat could spell a dangerous period for the monarchy, said a republican pressure group.
The new guidelines drawn up under supervision of Sir Gus O'Donnell, the Cabinet secretary, allow for a one-week delay in parliament's return for talks on a coalition if the vote is inconclusive.
The Tory leader has indicated he is prepared to ignore these rules and challenge the convention that dictates the Queen waits for a prime minister to tender his resignation rather than summoning him to resign.
"The next few days could be a very dangerous time for the monarchy," said a spokesman for republic. "If David Cameron tries to demand the keys to Downing Street it will put the spotlight firmly on the role of the monarchy.
"The Queen may find herself with an unpalatable choice on Friday: stick with convention or give Cameron what he wants. Either way it is a decision that will raise serious questions about how our prime minister is chosen," he said.
The Conservatives fear allowing Mr Brown to stay in office for another week could check the political momentum Mr Cameron would need if he wins the largest number of votes but falls short of an outright majority.
They accused Sir Gus of overstepping his constitutional authority by sanctioning new rules on which Cameron was not consulted.
"The idea that a courtier like Sir Gus O'Donnell will decide this is straight out of the Victoria and Albert Museum," one frontbencher told the Guardian.
"Sir Gus is damaged goods in our eyes. He is closely associated with Gordon Brown from his time in the Treasury."
Another said: "This is a way of saying if we have a hung parliament why worry about politicians? It is mildly anti-constitutional."
Downing Street said last night the new rules were designed to implement the recommendations of a 2007 cross-party Commons modernisation committee report. The report was accepted by the Speaker and by the government.
A Cabinet Office spokeswoman said: "The decision over when the House should return after an election is a matter for the government, not the Cabinet secretary or the civil service."
Sir Gus believed new guidelines would avoid uncertainty that could follow a hung parliament. He also extended government "purdah" rules for the election campaign to cover the negotiations so Brown would not be able to try to win over the Liberal Democrats with major government announcements.