Starmer calls on the UK Labour Party to unite in the "fight of our lives".

By Elizabeth Piper and Andrew MacAskill

LIVERPOOL, ENGLAND (Reuters) - UK Prime Minister Keir Starmer on Sunday called on his Labour Party to stop "looking at its own navel" and unite against Reform UK, accusing the rising populist party of planning a "racist policy" of mass deportation if it comes to power.

The Labour Party is well behind Reform in the opinion polls, and Starmer kicked off his annual conference in Liverpool by urging members to direct their anger at the opposing party, led by Brexit activist Nigel Farage, and not at his own leadership.

"We have the fight of our lives ahead of us, because we need to confront the Reform. We need to win it, so now is not the time for introspection or navel-gazing," he told BBC News. "We need to be united in this fight."

The next national election won't happen until 2029, but with Reform's growing popularity, Starmer is seeking a positive narrative after a difficult few weeks, when his deputy leader and his ambassador to the US were forced to resign.

The conference gives him the chance to mobilize the Labour Party and redirect the frustrations of critics who want his replacement, including the mayor of Manchester, Andy Burnham.

But the battle is difficult.

Starmer and his finance minister, Rachel Reeves, are under pressure within the party to increase spending and relax self-imposed fiscal rules aimed at balancing expenditure with tax revenue by 2029. But the government is expected to raise taxes in a budget on November 26 to adhere to the rules.

"The budget is an absolutely critical point in determining whether the direction will change," said Sharon Graham, head of Unite, one of the UK's largest trade unions.

"We should stop stalling and do it (change the fiscal rules). If this budget is essentially nothing... I think we have a real problem on our hands, because without the money to make the change, nothing will change."

STARMER CRITICIZED FROM BOTH THE LEFT AND THE RIGHT

But while members of the left-wing party criticize Starmer for failing to improve living standards as he promised in last year's election, centrists fear that markets may punish the government if it increases spending.

The central policy of Reform UK is to restrict immigration, a major concern for voters.

Starmer turned his fire against Farage's group.

"It's one thing to say that we're going to remove illegal immigrants, people who don't have the right to be here. I agree with that," he said.

"It's something completely different to say that we're going to approach people who are legally here and start removing them... I think that's a racist policy, I think it's immoral."

According to the Ipsos polling firm, only 13% of voters are satisfied with Starmer, while 79% are dissatisfied -- the worst rating for any prime minister since the data began being collected in 1977.

Starmer said he wasn't simply ignoring the criticism and that he would be judged on three things: improvements in living standards, better public services, and whether people felt safe in their homes.

(Reporting by Elizabeth Piper and Andrew MacAskill)