A spokesman for Boris Johnson has said: "Boris Johnson has repeatedly made clear he pays all taxes in full. Ken Livingstone knows this because he has been personally told by Boris Johnson during a private conversation at a business hustings just two weeks ago.
“Mr Livingstone repeated these false claims today, knowing full well they are not true, in a desperate attempt to avoid answering serious questions over his own tax affairs".
More top news
Dramatic footage captures the moment a three-storey building collapses in a matter of seconds having been hit by flood water.
Isaam Abuanza is the first practising NHS doctor known to have joined the so-called Islamic State in Syria.
Hundreds of steelworkers will march on Wednesday to highlight the crisis in their industry.