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 have now begun an extended Easter recess, earlier than planned, due to coronavirus.
Making his final Commons contribution in his four and half years as leader of the opposition, Mr Corbyn passionately urged the country to come together at this "hugely stressful" time.
"This crisis shows us how deeply we depend on each other. We will only come through this as a society with a huge collective effort.
"At a time of crisis no-one is an island, no-one is self-made… At times like this we have to recognise the value of each other and the strength of a society that cares for each other and cares for all."
Mr Corbyn’s final clash with Mr Johnson was dominated by the government’s response to the virus.
The opposition leader called 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”
Corbyn at PMQs
This was Jeremy Corbyn's 136th appearance at Prime Minister's Questions.
The Labour leader faced David Cameron across the despatch box 29 times, squared off against Theresa May 93 times and clashed with Boris Johnson just 14 times.
At his first appearance, on 16 September 2015, he tried what he called a "different style" to previous opposition leaders, asking David Cameron questions emailed in by members of the public.
He said he had received 40,000 replies to a call for questions to the PM - and he started with a question from Marie on housing.
He soon dropped this approach, although he would return to it occasionally during his time as Labour leader.
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 leader 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."
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.