* Ruling Conservatives defeated in parliamentary seat vote * Liberal Democrats overturn 23,000-vote Tory majority * Result viewed as backlash against PM Johnson

LONDON, DECEMBER 17

Boris Johnson's Conservatives on Friday lost control of a parliamentary seat they had dominated for nearly 200 years as voters turned against Britain's prime minister over a series of crises and scandals.

The defeat will intensify pressure on Johnson from within his own party, substantiating fears expressed publicly and privately that its reputation and electoral prospects are now suffering under his leadership.

The centrist Liberal Democrats party candidate, Helen Morgan, won the North Shropshire seat by nearly 6,000 votes, overturning a 23,000-vote Conservative majority from 2019.

"Tonight, the people of North Shropshire have spoken on behalf of the British people. They have said loudly and clearly: 'Boris Johnson, the party is over'," Morgan said in her victory speech.

"Our country is crying out for leadership. Mr Johnson, you're no leader."

The Conservatives had won every previous election for the mostly rural area of central England since the constituency was created in its current form in 1983. Conservative lawmakers have been dominant in the region for nearly 200 years.

The huge swing comes as Johnson faces criticism on several fronts, including over reports his staff held parties last Christmas when the country was in lockdown.

"Voters in North Shropshire were fed up and they gave us a kicking and I think they wanted to send us a message," Conservative chairman and lawmaker Oliver Dowden told Sky News. "I want to say as Chairman of the Conservative Party we've heard that loud and clear."

Nationwide opinion polls show Conservatives falling behind their main rivals, the Labour Party, following an outcry over lawmakers' second jobs, criticism of the way Johnson funded the lavish refurbishment of his flat, and a surge in COVID-19 cases.

The vote for the North Shropshire area, one of 650 seats in Britain's parliament, was called outside of the regular election cycle because the incumbent Conservative resigned after he was found to have broken rules on paid lobbying.

The government attempted to prevent that resignation by changing rules designed to stop corruption in parliament, but was forced to backtrack after the move provoked a backlash over integrity and trust under Johnson's leadership.

Mid-term elections, known as by-elections in Britain, are often used by voters to punish the ruling party, but the scale of the Liberal Democrat victory suggests deep public dissatisfaction with Johnson's government.

It still holds a large majority of the seats in parliament after a comprehensive election win in 2019 built on a promise to 'Get Brexit Done' that united traditional right-leaning Conservative voters with a swathes of new supporters.

North Shropshire was a pro-Brexit, staunchly Conservative area. Analysts say Friday's heavy defeat may further undermine Johnson's authority over lawmakers, some of whom are already in open revolt over plans to introduce COVID-19 passports.

Britain's next national election is due in 2024.