There are “hundreds” of Europeans now fighting in Syria, some of whom are with groups linked to al Qaeda, the Home Office has told MPs.

In an annual report on its Contest counter-terrorism strategy, the Home Office warned of the risk to Britain and other European nations posed by foreign fighters now gaining military experience in Syria.

The Home Office warning – based on assessments by British intelligence agencies – comes as ministers debate doing more to arm and support the rebels fighting the regime of Syria’s President Bashar al-Assad.

The uprising in Syria “has involved many organisations with different political views and tactics; some are connected with and supported by al Qaeda in Iraq,” the Home Office report says.