The monarchy could be plunged into a crisis by a stalemate election result, according to campaigners - raising serious doubts about the future role of the head of state.Anti-monarchy campaign group Republic has said that in the case of prolonged stalemate between Labour and the Conservatives there will be a need for an independent voice in the process.  That's a voice normally held by a head of state, but the Queen has vowed to stay silent.

If the Conservatives claim a moral victory by having the most seats yet Labour can defeat Cameron with SNP support then the crisis may last weeks.

With the prospect of market jitters and constitutional confusion plunging Britain into crisis it is a time when the country needs impartial leadership - something the Queen cannot provide.

Graham Smith, Republic's CEO, said today:

"We're now hearing reports the Queen will simply do as she's always done - follow the instructions of the PM. Nevermind that in times like this the PM has a vested interest in her actions."

"Where a country has an elected head of state, such as in Ireland, Italy or Greece, then a stalemate - like the one we may face this week - would be facilitated by a legitimate and accountable head of state.  A head of state can make plain the constitutional rules and can knock heads together, point out what is in the national interest and get parties to work together."

"The Queen has so far refused to get involved - and understandably so.  She knows that any involvement on her part would be very dangerous for the monarchy.  Immediately it would destroy the mirage of royal impotence."

"She is damned if she does - and may well be damned if she doesn't.  If the crisis lasts long enough people will demand someone does something and who should that someone be?"

"What we may need now is national leadership that can reach out past the political turmoil.  What we have is an impotent and silent head of state refusing to get involved for fear of her own position."

"The past few days we've seen the team captains squabble over the rules of the game.  We need a national, credible and impartial referee to steer us through this stalemate.  Imagine if we had an impartial elected figurehead who could be the authority on the way forward, with a mandate to fix the mess we might find ourselves in."

"The Queen may be faced with a choice: if she does nothing the nation staggers on through a deepening crisis.  If she acts she may end the political crisis but plunge the monarchy into a crisis of its own.  If she acts and gets it wrong the political crisis would carry on and the monarchy will be dragged down with it."

"Unfortunately the monarchy usually puts its own interests before those of the nation - so the Queen is likely to stay silent and impotent leaving the country in a protracted political quagmire."

"It's likely we'll continue to see this kind of election result in the future - that's why we need a democratic, accountable and impartial head of state, one who can steer us through these moments of political uncertainty."

"The worst solution is a result influenced by faceless bureaucrats such as the Queen's private secretary and the cabinet secretary.  This has to be an open and accountable process."