A few years ago, I went to a fascinating exhibition about books and babies at Cambridge University. They had on display some medieval manuscripts about weasels and child birth showing how, in the 13th Century, it was commonly understood that weasels conceived through the ear and gave birth through the mouth.

It was probably this biologically inaccurate conception that led to the idea of ‘weasel words’: the notion of unpleasant, shifty, vermin-like creatures emanating from people’s mouths, going around causing damage and harm to all and sundry.

I couldn’t help but think of weasels this morning when I saw the front pages filled with David Cameron’s hyperbolic warning that Brexit will trigger world war and genocide.

If you’ve been watching closely, you might have seen that ‘trigger’ has been the prime minister’s weasel word of choice in this referendum. If you google ‘David Cameron’ and ‘trigger’, you get almost 3 million results. If you google ‘Del Boy’ and ‘Trigger’ you get less than 30,000.

Whenever the prime minister is in search of a verb to describe the consequences of Brexit, the first thing he reaches for is his ‘trigger’.

In the House of Commons on 23rd February, Cameron said that, ‘If the British people vote to leave, there is only one way to bring that about, namely to trigger Article 50 of the treaties and begin the process of exit…’ He could have chosen from hundreds of other words in this context - ‘apply’, ‘appeal’ or ‘administer’ for instance (just to pick words beginning with the letter ‘a’) – but, no, he decided to go with trigger.

On 8th February, the prime minister said Brexit would ‘trigger a surge in refugee camps across South East England’. Again! Not ‘cause’, ‘create’ or ‘catalyse’ – trigger.

On 2nd March, he said that Brexit would ‘trigger economic shock across Britain’. Not ‘incite’, ‘initiate’ or ‘instigate’ - trigger.

The Prime Minister is clearly actively associating the idea of war/violence/death and Brexit in our mind.

Today he is making this connection explicitly, appealing to our rational minds with rational argument, but this is an idea he has been propagating for months subliminally.

The word ‘trigger’ even appeared in the very first paragraph of the controversial government information leaflet – ‘Why the Government believes that voting to remain in the EU is the best decision for the UK’.

The idea that Brexit would lead to war is clearly hyperbolic, but because of the priming that has occurred over the last few months, the British people are more likely to accept it. This is a sign the Remain campaign is winning the war of words.

In Only Fools and Horses, Trigger continously called Rodney ‘Dave’. It was a recurring sign of Trigger’s stupidity. In using the word ‘trigger’, Dave has proved that, when it comes to communication, he’s no fool.

Simon Lancaster is a professional speechwriter and author of Winning Minds: Secrets from the Language of Leadership.