Jeremy Corbyn has told ITV's Peston on Sunday security at Parliament "needs to be looked at" in the wake of the Westminster attack and called on the government to overhaul its counter-terror approach to stop Muslims feeling singled out.
In a wide-ranging interview with Robert Peston, the Labour leader said:
The government's Prevent counter-terror strategy is "often counter-productive" and needs to be broadened to stop it casting "suspicion" over the whole Muslim community in the UK.
He backed police's defence of Parliament but said the question of access to the building "needs to be looked at" after gates were briefly left unmanned.
He supported the policy of shoot-to-kill "in a wholly defensive situation" but cautioned: "You've got to be careful you don't end up with what we had in Ireland in the 1980s."
Addressing matters away from the attack, Mr Corbyn also said:
Labour is "ready" for an early general election should Prime Minister Theresa May decide to pursue one.
He would instruct MPs not to block a Government bid to repeal the Fixed-term Parliament Act to allow a poll to take place before 2020.
Labour would oppose plans to hand ministers "Henry VIII" powers to change European Union laws as they are repatriated to Britain without full parliamentary scrutiny.
He does not believe a second referendum on Scottish independence is a good idea but Westminster should not block it if the Scottish Parliament calls for one.
Speaking in the wake of the London terror attack, Mr Corbyn suggested the Government's deradicalisation programme needed to be reformed.
"I think what Prevent has often done is seen to target the Muslim community, not anybody else, looks to say there is a kind of suspicion over the whole community and it's actually often counter-productive."
When pushed on exactly what he believed needed to change, he said: "I'm saying broaden it into an agenda of inclusion. ... Focus it on all communities."
Wednesday's attack saw lone-wolf extremist Khalid Masood, who converted to Islam in adulthood, shot dead to end his car and knife attack in central London on Wednesday.
Mr Corbyn clarified that he supported the policy of shoot-to-kill "in a wholly defensive situation" but cautioned: "You've got to be careful you don't end up with what we had in Ireland in the 1980s."
Mr Corbyn backed the police response, saying: "The police did their best to protect Parliament and Keith Palmer lost his life trying to protect Parliament.
"But there is a question of ... access to the building and that needs to be looked at."
On the possibility of an early general election being called by the Prime Minister, Mr Corbyn said: "We are developing our policies but clearly if an election is called we can bring all that forward and we are ready, yes."
He added: "It wouldn't be just us actually because it (repealing the Fixed-term Parliament Act) requires two thirds of all MPs to vote for it.
"We would not block it, of course not, because if that's what is on offer, I don't know if that's in her mind or not. She certainly hasn't discussed it with me."