Vermont senator is latest figure to call for Democratic nominee to step down after sexual assault allegations

Republican leaders have moved to quash speculation about Mitch McConnell, the former Republican leader in the US Senate, amid a growing revolt over the lack of transparency around his health.

The 84-year-old Kentucky politician, who led Senate Republicans for longer than anyone in history before stepping down last year, was admitted to hospital on 14 June but his office declined to say what he was being treated for.