While Larry the Number 10 cat hogs the media limelight, it is the Foreign Office feline that has been hard at work.

Palmerston has been busy keeping the rodent population at bay, catching at least 27 mice since arriving on Whitehall in 2016.

And that’s official – the figure comes from documents released under Freedom of Information laws.

But those who look after the black-and-white cat, named after former foreign secretary and two-time prime minister Viscount Palmerston, have no doubt that number is an underestimate.

The recorded figures only include officially documented sightings and so is likely to be far higher.

Palmerston arrived from Whitehall from Battersea Dogs and Cats Home in 2016.

He lives in the shadow of Larry – but while the tabby and white feline is often seen leisurely strolling along Downing Street, basking in the spotlight, Palmerston has been at his most lethal.

Some Cabinet observers believe there is a feud between the two cats, but the reports have not been officially confirmed.

The FCO said it "does not keep an accurate figure for the amount of mice caught by Palmerston.

"The PUS’s (Permanent Under-Secretary, Sir Simon McDonald) office do receive reported sightings of Palmerston catching mice – so far (since Palmerston’s arrival in April 2016) this figure is at 27.

"This figure is likely to be much higher as these are only reported sightings."

The FOI request also reveals that Palmerston is typically but not exclusively fed Whiskas. The FCO said it could not provide financial details of Palmerston’s care but it added the bill was met voluntarily by staff.

(c) Sky News 2017: Foreign Office’s Palmerston is mouser in chief as Larry catnaps