David Cameron has been forced to deny Britain’s role in Afghanistan is suffering “mission creep” as he announced the deployment of 50 more troops and the extension of UK involvement into next year.

Despite previous plans for British soldiers to leave Afghanistan by the end of this year, the Prime Minister announced during a Nato summit in Warsaw that troops would remain into 2017.

He also deployed an extra 50 soldiers to help train Afghan defence and security forces as they tackle a resurgent Taliban close to 15 years after the original invasion.