Donald Trump criticises Republican House Speaker Paul Ryan over lack of support

Mr Trump complained, however, that he was being held back by Mr Ryan and other congressional Republicans who are stepping away from him in the hope of keeping their congressional majorities.

"Despite winning the second debate in a landslide (every poll), it is hard to do well when Paul Ryan and others give zero support!" Trump tweeted.

And then: "Our very weak and ineffective leader, Paul Ryan, had a bad conference call where his members went wild at his disloyalty."

That was a reference to a telephone conference call on Monday in which Mr Ryan made his position clear. He received some criticism from Trump supporters, but other Republicans clearly agree with the speaker.

While Mr Trump's candidacy has long exposed the party's divisions, Republican leaders had hoped to prevent an all-out civil war until after the election. But bickering has accelerated since last week's release of a videotape of Mr Trump showing the former reality television star using predatory language regarding women 11 years ago.

Despite winning the second debate in a landslide (every poll), it is hard to do well when Paul Ryan and others give zero support!

— Donald J. Trump (@realDonaldTrump) October 11, 2016

The chaos only deepened after Mr Ryan followed Mr Trump's Sunday night debate performance by essentially conceding a victory for Mrs Clinton, saying he would devote his energy to ensuring she doesn't get a "blank cheque" with a Democratic-controlled Congress, people on his private conference call with Republican House members said.

The head of the Republican National Committee veered in the opposite direction, declaring his full coordination with Mr Trump's embattled campaign.

Forty Republican senators and congressmen have revoked their support for Mr Trump - with nearly 30 of them urging him to quit the race altogether in recent days. Few of these were ever passionate Trump supporters, but the disarray underscores the predicament Republicans are in a month from the vote.

Republican officials fear Mr Trump's comments about women will drag down their own electoral prospects, if not stain the Republican brand for a generation. Others see no way for Republicans in some races to win without the backing of Mr Trump's loyal supporters.

Mr Trump apologised during Sunday's debate but also dismissed his comments about groping women without their permission as merely "locker room talk".

Mrs Clinton, for her part, touted new ideas on Tuesday to provide tax relief for families with young children. Her plan would double the Child Tax Credit and provide low-income families more money in refunds.

The "new tax credit will make their lives a little bit easier and help restore fairness to our economy," she said.

Mrs Clinton's focus on families came as her campaign grappled with newly-leaked emails shedding more light on the interplay among the former secretary of state's family, her husband's business relationships and her presidential ambitions.

The emails posted by WikiLeaks detail concern about former Bill Clinton aide Doug Band and the private corporate advisory firm he co-founded.

Women have the power to stop Trump.https://t.co/tTgeqy51PUhttps://t.co/VH3woeAf9Q pic.twitter.com/NjvbkPsjPR

— Hillary Clinton (@HillaryClinton) October 7, 2016

Daughter Chelsea Clinton in 2011 forwarded a news article about money Bill Clinton was receiving through Band's company and expressed alarm with its representatives calling British parliamentarians "on behalf of President Clinton" without her father's knowledge.

Mr Band tells John Podesta, Hillary Clinton's campaign chairman, that Chelsea "is acting like a spoiled brat kid" because she has not found her way in life.

WikiLeaks says the messages come from Mr Podesta's accounts. Mr Podesta has said messages may have been altered or edited to damage Mrs Clinton. It is not clear who hacked Mr Podesta's emails. Last week, US intelligence officials blamed Russia's government for a series of breaches and leaks intended to influence the presidential election.

Mr Ryan's pressing goal over the next month is preventing Republicans from losing control of the House, a scenario that seemed remote just a week ago. They hold a wide 246-186 seat majority.

But Trump supporters in Congress are furious that Republican leaders would turn their backs on the nominee. In the conference call with Mr Ryan, California Republican Dana Rohrabacher called Republican leaders "cowards", according to one participant, who like others, was not authorised to be quoted by name and demanded anonymity.