Tony Blair has backed calls for military intervention in Syria and suggested that Theresa May could avoid seeking Parliament’s approval before taking action against Bashar al-Assad.

The former prime minister has warned that failure to take action against the Syrian regime and its allies in the wake of a suspected chemical attack in Douma would only make them feel “emboldened to do more”.

The suspected chemical weapons attack late on Saturday killed at least 60 people, with more than 1,000 injured at several sites in Douma, a city near the capital, Damascus, according to a Syrian aid organisation.

Lending his support to the possibility of US-led airstrikes against the Assad regime, Mr Blair said that the UK should be “supportive” and that Mrs May should consider exercising the royal prerogative, which would avoid the need for a parliamentary vote.

“I think it is important provided that our advice about the source of the attack is the same as that of US that we would support US action,” he told BBC Radio 4’s Today programme.“If the US are taking action we should be prepared to be alongside them.

“It's just important to realise that if we allow it to go unchecked and unanswered then obviously the Assad regime and their outside backers, (and) in Russia and Iran will feel emboldened to do more, so I think it is important that we react."