LONDON (Reuters) - Frustrated at his inability to get a clear message across to British voters, Prime Minister Rishi Sunak called an election on Wednesday from a position of weakness.

Sunak, 44, heads into the election far behind the opposition Labour Party in opinion polls and increasingly dependent on a small team of advisers to steer him through what is set to be an ugly campaign.

He is struggling to assert control over his governing Conservative Party, with some lawmakers already discussing who will replace him after what many see as an inevitable election defeat.

Some party members say his tenure as prime minister has been marked by missed opportunities. Others that he was the wrong man for the job, more technocrat than leader.

One Conservative insider said he had become increasingly distant. "His team often just leave him alone in his office, he likes to have his own time," they said, on condition of anonymity. "His default is to tell people they're just wrong - his advisers and MPs alike."

It all seemed so different when the former investment banker and finance minister took office less than two years ago, inheriting an economy in crisis after financial markets balked at the under-funded tax and spending plans of his predecessor Liz Truss's short-lived premiership.

As Britain's fifth prime minister in eight years, Sunak was initially credited with restoring some stability with his focus on fiscal prudence, a less antagonistic attitude to the European Union and his success in restoring a power-sharing government in Northern Ireland.

But with many of the problems he has tried to tackle blamed on his own party, which has been in power since 2010, he has struggled to define what he stands for. More a stickler for detail than a big picture man, said one Conservative lawmaker.

Many of his manifesto commitments were drawn up by Boris Johnson, whose departure as prime minister in 2022 left the Conservative Party deeply divided and lurching to the right.

At a meeting of his parliamentary party in March, Sunak tried to rally lawmakers with the refrain that they were facing the "fight for our lives", but then quickly blamed a small coterie of members for "hurting everyone else", according to a lawmaker present at the meeting.

Sunak has tried several times to turn around the party's fortunes by recasting himself as a bold reformer, a stable technocrat and now someone who will "stick to the plan" rather than go "back to square one", a place where, he says, Labour will take Britain.

Two tax cuts in the last year failed to move the polls.

TOUGH POLITICAL INHERITANCE

When he replaced Truss after her chaotic 49 days in power in the autumn of 2022, he faced what some politicians said was the most difficult economic and political inheritance of any prime minister since World War Two.

The financial markets were spooked, debt levels were rocketing and his party was deeply split over which way it should turn to try to win over voters increasingly frustrated with the Conservatives' melodramas.

He reappointed veteran minister Jeremy Hunt as his finance minister, restoring some confidence to the markets and some of the party's reputation as a safe pair of hands on the economy.

Britain's youngest leader in modern times wanted to focus on delivery before the election, but some of his party colleagues say an obsession with detail often hampered quick decision-making.

Continual sniping from disenchanted Conservative lawmakers has done little to reduce a sense of frustration in Sunak's 10 Downing Street office that he has not been given the credit he deserves for what supporters see as his successes.

As party strains worsened, Sunak became more frustrated and isolated, surrounding himself with aides who had worked with him since he was finance minister.

"It's a mess there (at Number 10)," said one aide on condition of anonymity earlier this year. "Sunak is in a bunker. The focus is meant to be on delivery but getting decisions is very difficult."

PERSONAL WEALTH

Sunak, born in the southern English port city of Southampton in 1980 to Hindu parents of Punjabi Indian descent, is married to the daughter of an Indian billionaire and is one of the wealthiest politicians in Westminster.

Some critics say his vast personal wealth and elite, expensive education means he cannot relate to the problems faced by many people in Britain.

Voters are struggling with a cost-of-living crisis, the country's health service is facing some of the biggest challenges in its history and other infrastructure is in disarray.

Sunak is also under fire over several issues the right wing of his party feels he has done little to resolve - stopping migrant arrivals across the Channel, cutting taxes significantly and challenging what they see as a "woke" agenda in public life.

After weathering attempts to remove him, Sunak, whose approval ratings are even worse than those Truss had, enters the election with the hope that he can at least stem the haemorrhaging of support from the Conservatives.

"They used to say we (the Conservatives) have a narrow path to victory, but now it's so narrow you can't see it," said one Conservative lawmaker on condition of anonymity.

(Reporting by Elizabeth Piper; Editing by Alex Richardson)

By Elizabeth Piper