Video report by Political Correspondent Tom Sheldrick
Prime Minister Boris Johnson has visited Hartlepool, lending his support to the Conservative campaign ahead of a by-election in the town next month.
Mr Johnson toured Hart Biologicals, a medical equipment manufacturer in the town.
It follows a visit to Hartlepool Power Station by Labour leader Sir Keir Starmer two days earlier.
Jill Mortimer, a farmer and a councillor in North Yorkshire, is standing for the Tories. She ran unsuccessfully for parliament in Leeds East in 2019.
She will campaign to become the first Conservative MP for Hartlepool since the seat was created in 1974.
The May 6 contest comes 14 months after large sections of Labour's so called "red wall" fell in the 2019 general election.
Speaking to ITV Tyne Tees Political Correspondent Tom Sheldrick, the Prime Minister acknowledged the challenge his party faces in winning the by-election, but said "this is a moment of change and opportunity".
He said: "What we want to do is focus on the needs of the people of Hartlepool."
The opportunity is considerable because, if you look at it, we've done this massive plan for a Free Port which will contain the port of Hartlepool within it. So, what that does is, it makes it easier for companies to invest, to bring high-quality jobs.
Below is the list of candidates announced so far:
Conservatives - Jill Mortimer
Independent - Adam Gaines
Labour - Paul Williams
Liberal Democrats - Andy Hagon
North East Party - Hilton Dawson
Northern Independence Party - Thelma Walker
Reform UK - John Prescott
Social Democratic Party - David Bettney
Women's Equality Party - Gemma Evans
Nominations close on 8 April.