Rishi Sunak is expected to announce a 4 July general election in a statement in Downing Street.
The statement comes after a day of mounting speculation in Westminster.
Earlier, Foreign Secretary Lord Cameron cut short a trip to Albania, while Defence Secretary Grant Shapps delayed an overseas trip to attend cabinet.
In the Commons this afternoon, the SNP's Westminster leader asked Sunak if he was "feart" (scared) of holding an election.
Sunak replied that the election would take place in the second half of the year.
A lectern has now been brought out into Downing Street, where Rishi Sunak will shortly make a statement.
