Harris and Trump prepare for debate that could help decide the US presidential election

US Vice-President Kamala Harris and former president Donald Trump, the Republicans’ presidential nominee, will take the stage for a debate on Tuesday – a key test that pushed US President Joe Biden out of the race just a few weeks ago.

Coming less than two months before Election Day, the match-up was originally supposed to have been the second between Biden and Trump. But Biden stumbled so disastrously in the campaign’s first debate in June that Democratic Party leaders, including former House speaker Nancy Pelosi, either asked him to step out of the race or expressed concern about his ability to win.

ABC News’ “World News Tonight” host David Muir and anchor Linsey Davis will moderate the event at the National Constitution Centre, a private non-profit education centre and museum in Philadelphia dedicated to America’s foundational document.

The debate, which is to start at 9pm ET and run for 90 minutes, offers the candidates a chance to produce a clear lead in a contest that remains too close to call.

Many polls show Harris with a slight lead against Trump in the key battleground states of Wisconsin, Michigan and Pennsylvania – a reversal from Trump’s lead against Biden in these states before the president dropped out, but these numbers fall within margins of error and the contest still appears to be a dead heat overall.