A £1m donation from Harry Potter author JK Rowling kicked off the Labour party conference yesterday.

Ms Rowling, who is worth more than £550m as a result of the success of her series of novels about the boy wizard, attacked the Tory party’s family policy in a statement explaining why she had made the donation.

“I believe that poor and vulnerable families will fare much better under the Labour party than they would under a Cameron-led Conservative party,” she said.

“Gordon Brown has consistently prioritised and introduced measures that will save as many children as possible from a life lacking in opportunity or choice.

“The Labour government has reversed the long-term trend in child poverty, and is one of the leading EU countries in combating child poverty.

“David Cameron’s promise of tax perks for the married, on the other hand, is reminiscent of the Conservative government I experienced as a lone parent.

“It sends the message that the Conservatives still believe a childless, dual-income, but married couple is more deserving of a financial pat on the head than those struggling, as I once was, to keep their families afloat in difficult times.”

Last year the Tory leader set out his support for tax incentives to encourage people to get married, and faced down anti-gay critics in his own party:

“To those who think, even in 21st century Britain, that commitment and responsibility cannot be embraced by all, I say: you will not find a stronger supporter of marriage but why not also recognise the commitment that gay couples make to each other in civil partnerships?” he said.

“That’s modern Conservatism.”

Under the Civil Partnership Act, all benefits offered to married couples must be offered to gay and lesbian couples in civil partnerships.

The Prime Minister said he was “delighted” that JK Rowling, “one of the world’s greatest ever authors,” and a close personal friend of Mr and Mrs Brown, had donated to the Labour party for the first time.

“I thank her for supporting the Labour Party and our values of social justice and opportunity for all,” he said.

The party has debts of almost £18m, much it from the 2005 election, the most expensive Labour ever fought.

Labour general secretary Ray Collins was in an upbeat mood when he addressed conference yesterday.

He was appointed in June, months after the last holder of the post resigned amid the scandal surrounding donations.

In December he was named the 27th most influential LGBT person in British politics.

Peter Watt resigned as general secretary in November 2007 in the wake of the Abrahams scandal after claiming he did not know that third-party donations are illegal.

In his speech to conference yesterday, his first in his new role, Mr Collins said:

“It was our Labour government that made possible the civil partnership I entered in 2005.”

He also attacked the Conservatives and acknowledged the party’s parlous finances.

“Conference, we cannot dispute the Tories’ polling numbers, but let us be clear: there is no fundamental ideological shift towards them,” he said.

“Nearly half of all voters say the Tories are uncaring.

“And nearly half say they can’t be trusted.

“Yet I do not want to pretend the task ahead is an easy one.

“Since 1997, we have lived from election to election, and while this has served us well at the ballot box, it has now caught up with our bank balance.

“Our financial position remains difficult.

“And I want to thank all the members, unions, affiliates, and individual donors who have contributed to Labour this past year.

“The motives of those who give money to our Party are too often called into question, and make no mistake, without these donations, we would have no chance to compete with Lord Ashcroft’s billions.

“As general secretary, I promise you that I will put the long-term future of the Party front and foremost, spending your money where it needs to be spent to ensure victory at the next election, but also building an organisation that will endure as the only progressive force in British politics for the decades to come.”

Mr Collins, a former trade union official, said he will make the equalities agenda “my personal responsibility as General Secretary, not just because it is right but because it is crucial to our electoral success across all our communities.”