Pregnant Vogue Williams pulls off an incredible prank on co-host Jamie Theakston as she tricks him into thinking she's gone into labour live on Heart Breakfast

Vogue Williams tricked her Heart Breakfast co-host Jamie Theakston into thinking she had gone into labour during their Monday morning radio show.

The star, 40, is weeks away from welcoming her fourth child with husband Spencer Matthews, 38, and used her pregnancy for the incredible prank.

Heart producers were in on the trick, with Vogue using a water balloon under her chair to pretend her waters had broken live on air. 

Vogue, who is standing in for Amanda Holden on the show, started her performance by telling Jamie that her back was 'really sore' before dropping the water balloon.

'What just happened? Oh my God!' she shrieked prompting Jamie to ask her from across the desk 'You alright? Your waters not breaking, is it?'

'Oh, my God, yes!' Vogue told him. 'You’re f***ing kidding me.'

Jamie, a dad of two, remained incredibly calm as he came round to comfort Vogue, reassuring her 'You’re okay, you're alright' before asking 'Where’s Spenny [Spencer Matthews] at the moment?'

'I don’t know where he is. Oh, God where has everyone gone? They’re all just gone,' Vogue told him.

Jamie swung into action, telling the team to 'go and get a car' and insisting 'you’re not going to have the baby right now let me tell you.'

Vogue, at this point struggling not to laugh, groaned in reply and told her co-host I’m not having a baby in the Heart studios. No way!'

'You might have to literally wheel me on this chair,' she continued. 

'We can try get you to walk. We’ll go downstairs and get a taxi. We’ll get a taxi out the back,' Jamie told her before finally Vogue and her co-pranksters revealed the joke.

As a confetti cannon blasted, and Vogue fell on the floor in laughter, Jamie exclaimed: 'Oh, you’re kidding me? You little ****.'

'That’s so cruel. I was about to go with you in a taxi to the hospital.'

'You were so nice,' Vogue told him. 'I feel really guilty. Well, you know what, if anything ever went wrong, I’d like you to be there. You’re very calm under pressure. Well done!'

Fellow celebs agreed with Vogue in the comment section of Heart's Instagram post, with Capital's Sian Welby writing: 'I work on the floor below and I from this moment on, if there’s any emergency I’m going to get Jamie.'

'I agree with Sian,' Olly Murs wrote. 'I’m calling Jamie with any emergency from now on!! Cool as you like.'

Heart's Kelly Brook had a concern though, commenting: 'Omg I have to sit in that chair later!! I hope @petemayfm mopped it up.'

Listen to Heart Breakfast with Jamie Theakston and Amanda Holden weekdays from 6.30am-10:00 across the UK and on YouTube