Filming is underway in Cornwall on the seventh series of Doc Martin, with Martin Clunes reprising the role of the curmudgeonly GP Martin Ellingham and Caroline Catz as his estranged wife, Louisa.

When the last series ended in 2013, Louisa had decided to take their son James Henry to live with her mother in Spain while they try to work out their problems.

Martin Clunes said: “I’m thrilled to be back on the beautiful north Cornish coast to shoot series seven of Doc Martin. The Doc has some serious work to do if he is going to persuade Louisa to come back.”

Also returning to Doc Martin are Ian McNeice, who plays restaurateur Bert Large, Joe Absolom, as his son Al, while John Marquez returns to play eccentric local police officer PC Joe Penhale, who generally creates more problems than he solves as he attempts to instill law and order into the community. In the new series he is getting to grips with a newly issued Taser gun, with disastrous consequences.

Dame Eileen Atkins will again play Doc Martin’s formidable Aunt Ruth. She doesn’t suffer fools, just like her nephew. Jessica Ransom also returns as receptionist Morwenna Newcross, who is looking for a pay rise for trying to keep the doctor in line.

Audience figures since Doc Martin was introduced in 2004 have averaged in excess of nine million viewers. Filming is underway on location in the Cornish town of Port Isaac.

More than 800 local people turned up for auditions in Port Isaac to play extras in the new series earlier this month. As the doors of the church hall opened for the auditions there was a queue of 150 babies in prams and pushchairs hoping to be selected for the role of 11-month-old James Henry.