With just under a month to go before the 2015 general election, the Conservatives got down and dirty. Defence Secretary Michael Fallon used an article in The Times to accuse Ed Miliband of being willing to "barter away" the UK's nuclear deterrent, Trident, because the Labour leader, who beat his brother David to the post, was a power-hungry "backstabber" ready to get into bed with the SNP.

The reaction to Fallon's ungentlemanly conduct caused shock and disgust, but the Conservatives double-downed on the personal attacks against Miliband. Fallon hit the airwaves and David Cameron claimed his defence secretary had made a "very important point...Ed Miliband can only get to Downing Street on the back of SNP support".

Miliband, for his part, was sucked into the row and was forced to state that he would never compromise Britain's national security.

Soon posters of Miliband in the pocket of Alex Salmond, then SNP leader, began to pop-up in marginal seats across England. The strategy had the hallmarks of a Lynton Crosby campaign.

The Australian election guru, otherwise known as "the Wizard of Oz", was behind a string of federal election victories for The Liberal Party before he turned to British politics and helped Boris Johnson win the 2008 and 2012 Mayor of London elections.

The surprise majority for the Conservatives at the 2015 general election earned Crosby, 60, a knighthood in 2016. May's call for a general election on 8 June will see the top strategist teaming up with the Tories once again.

"Lynton is on board, and we are delighted to have him. He is the best in the business," a Number 10 source boasted to The Sun. But will Crosby and the Conservatives turn to a so-called "dead cat" strategy again?

"Let us suppose you are losing an argument. The facts are overwhelmingly against you, and the more people focus on the reality the worse it is for you and your case," Boris Johnson wrote in The Telegraph in 2013.

"Your best bet in these circumstances is to perform a manoeuvre that a great campaigner describes as "throwing a dead cat on the table, mate".

"That is because there is one thing that is absolutely certain about throwing a dead cat on the dining room table – and I don't mean that people will be outraged, alarmed, disgusted.

"That is true, but irrelevant. The key point, says my Australian friend, is that everyone will shout "Jeez, mate, there's a dead cat on the table!"; in other words they will be talking about the dead cat, the thing you want them to talk about, and they will not be talking about the issue that has been causing you so much grief."

Tory campaign poster
Tory campaign poster showing Ed Miliband in the pocket of Alex SalmondGetty