Story highlights Evie and Ossie will help catch mice in the Cabinet Office

They bring the number of British 'diplocats' to five

Correction: Evie and Ossie will actually be based at the Cabinet Office, leaving Larry to roam 10 Downing Street.

London (CNN) Larry, 10 Downing Street's chief mouser, has some more competition -- there are two new diplocats in town.

On Friday, the UK's Cabinet Office announced the arrival of Evie and Ossie.

The breaking news came from the official Cabinet Office Twitter account . They join the Treasury Office's Gladstone and the Foreign Office's Palmerston.

Welcome to our new cats Evie & Ossie, rescued by @CeliaHammond. Arrived in time to celebrate our 100th birthday & catch some mice! #CO100 pic.twitter.com/DxC1ucXFyC — Cabinet Office (@cabinetofficeuk) 9 December 2016

Ossie pays homage to Sir Edward Osmotherly, who drafted important rules for civil servants . Evie, the first female feline to join the Diplocats, is named after Dame Evelyn Sharp, the first lady to become permanent secretary , a senior position in the British government.

They're big names to live up to, but Larry -- often seen lazing around the door of nearby No. 10 -- doesn't seem worried.

Larry was rescued from life as a stray by former British Prime Minister David Cameron.

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