But under the Fixed-Term Parliaments Act, MPs need to vote for an early election to allow one to take place.
Mr Johnson has twice before tried and failed to get the Commons to back a snap poll.
Opposition parties refused to support the moves because they wanted to remove the prospect of a no-deal Brexit at the end of this month.
With the deadline pushed back even further, they should in theory agree to an early election. But this is not a certainty.