Brazil’s presidential front-runner, Jair Bolsonaro, lost 40% of his blood after he was stabbed on Thursday, hospital officials say.

The far-right politician was attacked at a campaign rally in Minas Gerais.

Doctors say he suffered a deep and life-threatening stab wound in his intestines, but is now recovering well.

The controversial politician won supporters for his tough stance on crime, but has outraged many in Brazil with racist and homophobic comments.

Polls suggest he will get the most votes in the first round of the October presidential elections if former President Luis Inácio Lula da Silva remains blocked from standing, but is unlikely to win a run-off.

Left-wing Lula had been the long-standing favourite but he is currently in prison, appealing against a ban on his candidacy that was imposed after his conviction for corruption.

Hospital director Eunice Dantas told reporters on Friday that Mr Bolsonaro had lost more than two litres of blood, and was in shock, when he arrived.

He is now stable and “in excellent clinical condition” after being operated on, she added, although he will need to spend at least a week in hospital.

Mr Bolsonaro’s family say the knife had penetrated 12cm (4.7in) into his abdomen, Reuters news agency reports.

He has now been transferred to a hospital in Sao Paulo.

In a video circulated on social media on Friday, Mr Bolsonaro spoke from his hospital bed, saying he had been in “intolerable” pain and had “never hurt anyone”.

His son Flavio also tweeted a photo of his father making the thumbs-up gesture from his hospital bed.