Jeremy Corbyn has said “his voice will not be stilled” as he took part in his final Prime Minister’s Questions as Labour leader.
He warned the PM not to deliver his political “obituary”, as he would not stop campaigning for social justice.
Boris Johnson paid tribute to his opponent’s “sincerity and determination to build a better society”.
MPs are set to begin their Easter recess later on Wednesday, earlier than planned, due to coronavirus.
The Commons will not return until 21 April at the earliest, by which time Labour will have a new leader.
Mr Corbyn’s successor is due to be announced on 4 April, following a three-month leadership campaign triggered by Labour’s heavy election defeat in December.
Mr Corbyn’s final clash with Mr Johnson was dominated by the government’s response to the virus.
The opposition leader calling on the PM to ramp up levels of testing, ban all non-urgent construction work, give more help to the self-employed and renters facing eviction and to do more for Britons abroad who felt “abandoned”.
In a highly unusual move, the session was extended from half an hour to an hour to allow more members to ask questions. As part of this, Mr Corbyn was allowed to ask 12 questions, rather than the usual six.
Marking his opponent’s last appearance, the PM said that while the two men “did not agree” on everything, his “service to his party and country in a difficult job” should be recognised.
And he joked that Mr Corbyn’s vow not to retire from frontline politics would be “warmly welcomed by his successor”.
Mr Corbyn, who was first elected Labour in 2015, responded by thanking the PM for his “warm words” and insisting that he would continue to play a prominent role in British politics.
“My voice will not be stilled. I will be around, I will be campaigning, I will be arguing and I will be demanding justice for the people of this country and, indeed, the rest of the world.”