Britain’s governing Conservative Party suffered crushing defeats in two parliamentary elections in a new blow to its embattled leader, Prime Minister Rishi Sunak.

Election results announced early on Friday showed the Conservatives had lost seats they had held in Kingswood, near Bristol, and in Wellingborough, in Northamptonshire — a district that had been regarded as one of the party’s more impregnable strongholds. Votes had been cast on Thursday to replace two Conservative lawmakers who had quit Parliament.

With a general election expected later this year, the defeats are likely to compound Sunak’s difficulties at a time when the British economy is shrinking, interest rates are high and Britain’s health service seems to be in a state of almost permanent crisis. Opinion polls show his party trailing Labour by double-digit margins.

The first result came from Kingswood, where Labour defeated the Tories by 11,176 votes to 8,675. In Wellingborough, Labour performed even better by securing a seat that, in the last election, the Tories won by more than 18,000 votes. This time, Labour won by 13,844 votes to 7,408.