Labour is now in with a “fighting chance” of winning the next election after Ed Miliband's conference speech fired the “starting gun” of the campaign, Harriet Harman claimed today.
The party's deputy leader said Mr Miliband, a keen baseball fan, had "knocked the ball right out of the park" with his key note address earlier this week.
Closing the five-day conference in Manchester, Ms Harman said it had been a "special" game-changing gathering that had emboldened the party.
But she warned there must be "no no-go areas" when it comes to campaigning in the run-up to the expected 2015 vote and called on members to work as a team to fight the Tories and Liberal Democrats.
The shadow culture secretary said: "This week has been special, this week the game has changed.
"We know we have big challenges ahead but we leave Manchester emboldened, enthused, with a strong sense of purpose.
"We have grown in confidence, we have grown in self-belief.
"This country needs a government of and for all its people, not a coalition that plays divide and rule.
"This country needs a One Nation Labour Party and a One Nation Labour government."
She added: "It's been a great week for the Labour Party and it's been a great week for Ed Miliband."
Ms Harman rounded on the Lib Dems for backing tax cuts for millionaires and accused Deputy Prime Minister Nick Clegg of propping up a "miserable Tory government".
The deputy leader also launched a direct attack on Business Secretary "saint" Vince Cable after speculation that Labour would find it easier to work with the left-leaning cabinet minister in a coalition after the next election.
She said: "People say you get the politicians you deserve but no-one deserves Nick Clegg.
"Calamity Clegg who has propped up this miserable Tory Government every step of the way.
"It's no wonder Vince Cable is on manoeuvres.
"But let's not forget Saint Vince is in it up to his neck too. After all, it was his policy to treble tuition fees.
"So I have a message for Vince. Don't bother texting Ed - he's changed his number.
"We have a first-past-the-post system and voters get just one vote - we're saying to them vote Labour.
"We are not fighting to be part of a coalition Government - we are fighting to win."
Ms Harman also mocked the Prime Minister telling conference "Women are finding it hard to hang onto their jobs - and that's just the women in David Cameron's Cabinet.
"You know Angry Birds used to be David Cameron's favourite computer game - now it's his pet name for Caroline Spelman and Nadine Dorries."
The conference ended with the traditional singing of Jerusalem and the socialist anthem The Red Flag, accompanied by a group of young Manchester singers called Re:verb.