Theresa May has said she plans to say sorry to activists at the Conservatives' annual conference in Manchester for the party's performance in the snap election she called earlier this year.

The apology comes as the Prime Minister launched a bid to target young voters with a tuition fee freeze and a £10 billion boost for first time buyers as she tries to stop Tory tensions over Brexit dominating the gathering.

The move came amid renewed Brexit back-biting after another incendiary intervention by Foreign Secretary Boris Johnson who laid down a raft of red lines for EU withdrawal including an insistence that a transition phase must not last "a second more" than two years.

As Conservatives converged on Manchester, the Prime Minister pledged to "look again" at student finance after the party's disastrous general election showing.

Attempting to shift the focus from Brexit to a good news domestic agenda, Mrs May announced that tuition fees will be frozen at the current £9,250 level until 2019, rather than increase with inflation by £250.

She said she would tell activists on Sunday that she takes responsibility for the June 8 election, in which she lost her overall majority in the House of Commons.

"I have been very clear that I called the election, I led the election, I take the responsibility and I am sorry that some very good Members of Parliament lost their seats and some very good candidates didn't gain seats," Mrs May told BBC1's Andrew Marr Show.

"I have spoken to my Members of Parliament and I will be speaking later today to the party activists."

Mrs May said that the message she took from the election was that Tories need to "listen to voters", who appeared to feel "even more keenly" than she had realised the pressures which she identified when she came into power promising to help the "just about managing".

Under Mrs May's plans, the amount graduates can earn before making student loan repayments will also rise from £21,000 to £25,000.

The figure will then increase in line with earnings after next year, with the Tories saying the package will produce a saving of £360 in 2018/19 for graduates earning at least £25,000.

In a bid to help young people get on the housing ladder, Chancellor Philip Hammond is announcing a £10 billion expansion of the Help to Buy: Equity Loan scheme in order to aid 135,000 new purchasers.

The Foreign Secretary's Brexit demands drew a stern rebuke from former education secretary Nicky Morgan who said people behaving like Mr Johnson have "no place in a responsible government".

Writing in the Independent, Ms Morgan said: "Those who are pushing this agenda have no place in a responsible government - it is a dereliction of their duty to act in the national interest. And it has to stop."

Scottish Conservative leader Ruth Davidson also entered the Tory fray, calling for "serious people" to take charge of the Brexit process.

Remain-backing Tory MP Anna Soubry said on Twitter: "People are fed up with Tory wars and Brexit mixed messages. Boris Johnson must grow up or go."

Mrs May, who celebrates her 61st birthday on Sunday, made it clear she intends to remain in power.

She told the Sunday Telegraph: "I will fight the next election. I'm not a quitter, I'm in it for the long term and I believe there is a long-term job to do."

The comments came as the Observer reported that Communities Secretary Sajid Javid declined to reply when asked if Mrs May should lead the Tories into the next election.

Mr Javid laughed when asked the question, then stood up and declared "I think we are out of time," the newspaper said.

As speculation over Mrs May's future continued, Mr Hammond dismissed claims that he had offered his backing to Mr Johnson for a leadership bid as it became clear the Tories had lost their Commons majority.

Mr Hammond told the Mail on Sunday reports that he texted the Foreign Secretary at 4am on the morning after polling (Friday June 9) to express support for Mr Johnson when it looked as if the PM might have to resign were not true.

Tory party chairman Sir Patrick McLoughlin said there was always "chitter chatter" about the leadership at conference time but Mrs May was a "strong leader and is the right person to take this country forward" and lead the Brexit talks.

Asked about reports that Mr Johnson believes Mrs May has "a year at most" left in the job, Sir Patrick told LBC Radio: "I have not seen Boris's comments. If he said that I don't think that's right. I think she is the person that is right for the Brexit negotiations, which are very important."

Mrs May defended the reforms to the student finance system - and refused to rule out moving to a graduate tax system in future.

Critics of the reforms have pointed out that the changes will still leave students tens of thousands of pounds in debt and the change to repayment thresholds will save graduates around £1 a day.

The Prime Minister said when the fees were hiked it had been expected that there would be a "diversity in the system" rather than most universities charging the maximum amount of fees.

Asked if there could be a graduate tax instead of the current system, she said: "By looking at it again we will be looking at the issues that people are raising, we will be looking at where the system has worked, we will be looking at the concerns that people have."

She warned a Labour government would result in a run on the pound and an economy "going into freefall" as she was challenged about her own stewardship of the economy.

Mrs May said getting a "successful future" after Brexit was one issue that needed to be addressed as she promised a "balanced approach" to the nation's finances.

That meant being "careful" with the public sector finances while ensuring that "across the whole of the country people are seeing the benefits of free trade, the benefits of the free market economy".