London, May 7 (IANS): The UK's ruling Conservative Party has snatched a historically left-wing seat from the opposition Labour in a tense by-election in England.

Conservative party candidate Jill Mortimer won the north-east England seat of Hartlepool with a large majority, beating opposition Labour party candidate Paul Williams, reports dpa news agency.

She described it as a "truly historic" result.

It is the first time since its creation in 1974 that the seat has been won by a Conservative politician.

Previously it had only been held by Labour, at one point, a candidate who ran as an independent.

The result is a boost for Prime Minister Boris Johnson despite a rocky few months for the premier, with the country's successful vaccine campaign appearing to be a key factor.

It is equally a blow for Labour party leader Keir Starmer, who has only been chief for a year.

The win will make no difference to Johnson's influence in the British parliament, however, as his party already holds a majority.

The by-election was held on Thursday, the same day as local and mayoral elections across England, and votes for the Scottish and Welsh Parliaments.