(Advisory: Please note slang in final paragraph)

Slideshow ( 4 images )

LONDON (Reuters) - Thousands of anti-Brexit protesters on Saturday displayed a sometimes bizarre array of placards to lampoon British leaders and Brexit with references to everything from fields of wheat to ornithology.

Britain is in its biggest political crisis for decades as Prime Minister Theresa May struggles to gain approval for her Brexit deal after Britons voted by 52 percent to 48 percent to leave in 2016.

Amid deepening anger at the political deadlock, thousands of people took to the streets to march through central London to demand another referendum.

Many turned to satire to express their frustrations.

“Pants to Brexit,” was spelt out on white underwear pegged across three washing lines held above the crowd.

Popular targets on the march included Prime Minister May, prominent leave backers Boris Johnson, David Davis and Nigel Farage, and former Prime Minister David Cameron, who called the referendum.

“Running through the fields of wheat and straight off a cliff,” one protestor wrote, alluding to an interview in which May provoked mirth by saying the naughtiest thing she had ever done was to run through wheat fields.

On another sign, an intricate sketch of May replaces the character in Edvard Munch’s famous painting “The Scream”, a lithograph print version of which will feature in an exhibition at the British Museum which opens in April.

“Make it stop,” it reads by May’s anguished face, with the words “Article 50 Repeal” in the background, in reference to her power to unilaterally revoke the notice Britain gave that it would leave the EU.

But opposition Labour leader Jeremy Corbyn, who has said he will deliver Brexit and equivocated over the terms of a new vote, also was criticized. One sign blended the facial features of Corbyn and May, saying “partners in crime”.

Some of the signs were more playful and provocative.

“Pulling out doesn’t work,” read one, referring to an unreliable contraceptive method, while others poked fun at the drudgery of dating apps and the appeal of the EU’s features by comparison: “The only Single Market I want to leave is Tinder.”

One placard provided a bird-guide to different species of tit, with pictures of examples such as blue tit and coal tit, before concluding with David Cameron, labeled a “colossal” tit - a British phrase for massive idiot.

Another said simply: “Brexit will be as shit as this sign.”