I KNEW the fallout from this tightest of general elections could be complicated when I found myself wondering if Helen Mirren will play a part in it…

With the two big parties neck-and-neck – the latest projection is for the Conservatives to win 278 seats and Labour 269 – a second hung parliament seems ever more likely.

So, intrigued to find out what might happen next, I popped along to a chat with the Institute for Government, which was set up to worry about this sort of stuff.

Now, most people who pay attention to politics already know the next Government will probably not be decided as swiftly as five years ago, when the Coalition was born.

On that occasion, Gordon Brown took abuse as the “Scottish squatter”, but was gone from Downing Street in just four days – lightning quick by the standards of many other European countries.

We also know the State Opening of Parliament is booked for May 27, which suggested clarity within three weeks of polling day on May 7.

But what is now clear is that if David Cameron does well enough to try to cling to office, by exploring deals with other parties, it will be June before he can be forced out.

And, in those circumstances, the Queen’s Speech, Parliament’s day of glorious pomp and majesty, will go ahead without…Her Majesty.

If the result leaves neither the Tories nor Labour able – or willing – to form an obvious Coalition, then Mr Cameron will stay in No 10 until he can test whether he still has Parliament’s support. That test would come in a vote on his new legislative programme, the Queen’s Speech, but not until early June, the week after it is delivered.

If the anti-Conservative forces are enough to defeat Mr Cameron, he would face an immediate no-confidence vote – and irresistible pressure to resign after that, too, was lost.

The Queen would then ask Ed Miliband to try to form a Government, giving the Labour leader 14 days to win a confidence motion – or plunge the country into a second election within weeks.

So far, so complicated – but there is the added factor of the determination of Royal staff and Government officials to keep the Queen far away from controversy until the lie of the land is clear.

Pointing out she stayed at Windsor Castle during the 2010 Coalition talks, Peter Riddell, the Institute’s director, said: “They want to avoid the Queen being dragged into what is a highly-contentious situation.”

On the Queen’s Speech on May 27, he added: “If there’s any doubt about the Government, we won’t see the Queen.”

At the moment, my mind wandered to the question of who could best stand in for Lizzie – and quickly settled on the Oscar-winning portrayal by the wonderful Helen Mirren.

Sadly, if unsurprisingly, that’s not on the cards. The monarch’s place would be taken by the less stellar figure of Tina Stowell, the Conservative Leader of the Lords.

She is best known for insisting she could stand her ground in the male-dominated Tory Cabinet, saying: “Noble Lords might want to think of me as the Beyonce of their Lordships’ House.”

So, no Queen-impersonator – but great drama nonetheless. Who said politics is dull?