LONDON (Reuters) - The fur is flying on social media as Britons prepare to vote on Thursday (June 23) on whether the United Kingdom should remain in the European Union.

The hashtags #CatsAgainstBrexit and #CatsForBrexit flooded Twitter on Monday and Tuesday, as pro- and anti-independence citizens tweeted feline photos and messages imploring voters to side with them in the referendum on Thursday on a British exit or "Brexit".

"Naughty Cat worries we'll be on the outside looking in, missing influence we once had #CatsAgainstBrexit," tweeted Nicola Blackwood (@nicolablackwood), a conservative politician and member of Parliament for Oxford West and Abingdon, late Monday.

The tweet included a photo of a cat looking through a glass window.

"My cat is praying for #Brexit #CatsForBrexit," tweeted Ms Maria Caulfield (@mariacaulfield), a member of Parliament for Lewes, along with an image of a cat covering its face with its paws.

Others found comic relief in the hashtags, likening the Brexit debate to cats' sometimes fickle behaviour.

"We're voting in. Are you sure? In. Or out? Definitely in. In, okay. Don't shut the door. #CatsAgainstBrexit #fickle," tweeted GFDavies (@gailfdavies), with a photo of two cats standing in a doorway.

The probability of a Brexit by 2017 was at 26 per cent on Tuesday, according to the online betting platform PredictIt.