UPDATE 1-In northern England's Hartlepool, UK PM Johnson faces test

* Vote a test for Johnson on COVID, Starmer's future

* UK PM Johnson sends personal message

* Labour has held Hartlepool for decades (Adds Johnson comment)

By Elizabeth Piper

LONDON, May 6 (Reuters) - The northern English town of Hartlepool was voting for a new member of parliament on Thursday, a test of Prime Minister Boris Johnson's handling of the COVID-19 pandemic and the future of the opposition Labour Party's new leader.

Johnson's governing Conservative Party hopes to break Labour's decades-long hold over Hartlepool, a former industrial port town, to bolster a 2019 election victory in which he won votes from traditional opposition supporters.

If the town does elect the Conservative candidate, farmer Jill Mortimer, it will also raise questions over the leadership of Keir Starmer, elected last year as a new face to lead Labour to electoral success after a disastrous showing in 2019.

Governing parties in Britain rarely win new seats at so-called by-elections to the Westminster parliament, and a Conservative victory over Labour candidate Paul Williams would suggest that the often gaffe-prone Johnson was also managing to shrug off allegations of cronyism, which he denies.

"Hi folks, I'm urging everybody to get out today and vote for Jill Mortimer in Hartlepool," Johnson said on Twitter, a personal message that underscores how much firepower the Conservatives have channelled into winning the race.

"I think she's got a fantastic plan for change and improvement in Hartlepool," said Johnson, who visited the town three times before the vote.

He again pushed his message that only the Conservatives can create new jobs in an area where the demise of heavy industry has left many unemployed.

The vote is one of dozens of elections taking place on Thursday, ranging from those to local councils to parliamentary votes, in Scotland, England and Wales, gauging support for Britain's two main parties and in Scotland's case, the depth of backing for its leading party's push for independence.

Both parties have suggested these polls, especially in Hartlepool, will feel very different. The coronavirus crisis has curtailed campaigning and overshadowed traditional election topics such as wider health policy, education and transport.

Labour fears the Conservatives will be boosted by the rapid roll-out of the government's COVID-19 vaccination programme and the loosening of coronavirus restrictions.

Instead it has been pushing its message that the Conservatives enjoy "one rule for them, another for the rest of us" particularly over how Johnson paid for the lavish refurbishment of his apartment in Downing Street, something Britain's election watchdog is investigating.

Johnson says he has paid the cost and obeyed the rules.

Starmer says Labour is fighting for every vote in the elections and has promised to take responsibility "whatever the results are". (Reporting by Elizabeth Piper; Editing by Giles Elgood)