The Finsbury Park terror suspect had been intending to target a Muslim march in London but arrived too late and so allegedly attacked worshippers at a mosque instead, it has been claimed.
Darren Osborne, 47, told locals in a Cardiff pub on Saturday night he was “going to do something about them”, after hearing there was a Ramadan rally planned in the capital the following day.
Hours later police missed an opportunity to prevent the attack when he was reported for being drunk and asleep in the cab of his hire van, but was not arrested.
Mr Osborne, a father of four from Cardiff, remains in custody at a south London police station, where he continues to be questioned in connection with the terrorist attack in north London in which one man died and nine others were injured.
The landlord of his local pub, Andy Parker, claimed the day before the incident he had been ranting about the pro-Palestinian, Al Quds day rally, which took place on Sunday afternoon in central London.
Mr Parker, who runs the Hollybush pub in Pentwyn, said: “The gentleman came in and was very political with everyone he spoke to.
“He was very motivated about the Muslim Al Quds Day rally going on on Sunday and London and kept saying: ‘Our brothers and sisters are dying and someone needs to do something about it’.
“He kept saying he would do something about it, but he kept going on about it, and was saying we need to ‘stand up to Muslims’ it is ‘time we did something about them’.
One of the customers added: “He was going on about this march on Sunday and making notes on a piece of paper.
“He just kept saying ‘Al Quds’ and going on about how wrong it was that Muslims were taking over.
“A group of the boys told him to shut up and got into a row with him and eventually he finished his drink and left.
“Now I think about it maybe his plan was to target this march but then went to the mosque when that didn’t work out.”
After leaving the pub, Mr Osborne fell asleep in the white hire van, that was used in the terror attack the following day.