The alleged chemical attack in Douma seems to have brought the issue of defence to the forefront of voters’ minds

The Conservatives opened a five-point lead over Labour this week after the intervention in Syria, the biggest advantage since the botched 2017 election.

A YouGov poll for The Times put the Tories on 43 per cent, up 3 points on the week before, and Labour on 38 per cent, down 2 points, with the Lib Dems on 8 per cent, down 1. The changes are within the margin of error but come at a time when the poll shows defence and security are increasing in importance to voters.

The topic of defence and security is up five points, according to a question where voters are asked to pick the three most important subjects. Brexit remains the top subject, followed by health and immigration.