Matt Smith’s ex-girlfriend Daisy Lowe and Downton Abbey star Jessica Brown-Findlay are among those tipped to become Doctor Who‘s new sidekick, following the news that Karen Gillan is leaving the show.

Bookies have named 22-year-old model and actress Daisy as the 10-1 third favourite to join the Doctor in the Tardis after Karen – who plays Amy Pond in the series – makes her exit.

However, she could face some stiff competition, with Downton‘s Jessica the 4-1 favourite to take the role, followed by model Lily Cole at 6-1.

Actress-turned-Strictly Come Dancing queen Chelsee Healey is also in the running at 12-1 – but bookmakers Ladbrokes have hinted that bringing Daisy into the show could make for an explosive combination.

‘Ratings would surely rocket if Lowe and Smith were thrown together,’ spokeswoman Jessica Bridge said.

Daisy recently split from Matt after they had been together for 18 months, but on Friday the pair were seen hugging outside her North London home before going inside – sparking rumours they may have rekindled their romance.

According to an eye-witness, Matt had just gifted Daisy with a new car as an early Christmas present – further lending weight to the reports of a reunion.

Meanwhile Doctor Who fans have taken to the internet to express their disbelief and anger over Karen’s impending departure – in what has been described as a ‘heartbreaking storyline’ due to air next year.

‘I can cope with a lot of things,’ one fan, Graham Pugh, said on Twitter, ‘but Amy Pond leaving Doctor Who could push me over the edge.’

Another fan, Aoife Wilson, added: ‘If you listen carefully you can hear the sound of a million hearts breaking in unison.’

Matt, meanwhile, said that he was ‘very disappointed’ that Karen, 24, was leaving.

The actress – who also stars as model Jean Shrimpton in the upcoming BBC Four drama We’ll Take Manhattan – has previously said that she is keen to do more theatre.