The Canadian government indicated on Thursday that it intends to speed up proposals to toughen the country’s anti-terror laws in the wake of the attack on parliament in Ottawa, including a measure that would allow “preventative detention”.

As the House of Commons opened to rapturous applause for the sergeant-at-arms, the ceremonial security chief who prevented further tragedy by apparently killing the perpetrator of Wednesday’s brazen assault, prime minister Stephen Harper indicated that his government was resolved to toughen the country’s security legislation.

The governing Conservatives have made no secret of their plan to install new anti-terror powers, giving the Canadian Security Intelligence Service (CSIS) more powers to track, investigative and detain would-be homegrown terrorists. Harper promised the proposals would be brought forward.

“They need to be much strengthened, and I assure you, Mr Speaker, that work which is already under way will be expedited,” Mr Harper said.

Details of those new powers have yet to be released, but justice minister Peter MacKay indicated to reporters that they will include measures to allow the preventive detention of suspected would-be terrorists.

“We’re examining all those sections of the criminal code, and all measures under the law that will allow us, in some instances, to take pre-emptive measures,” he said.

When asked about the schedule for the new legislation, government House leader‎ Peter Van Loan refused to say exactly when a bill would come forward, acknowledging only that Wednesday’s events had changed the context. A security bill, was originally due to be tabled on Wednesday morning.

The Harper government contends that Canada’s security agencies, tasked with thwarting attacks, are demanding greater powers, arguing that the current arrangements for judicial oversight hampers their ability to deal with imminent threats.

But despite the cross-party show of unity and defiance on Thursday, opposition parties are warning that the government, in the wake of the Ottawa attack, is rushing to adopt expansive new spying powers without considering the consequences.

The leader of the official opposition party, the New Democrats, Thomas Mulcair, said that one act of terrorism should not bend the Canadian way, nor should it even hamper the weekly yoga class that takes place on the front lawn of Parliament – a symbol, he said, of the openness of the Canadian legislature.

Kevin Vickers received a hero’s welcome for apparently killing the gunman inside in Ottawa’s parliament building. Photograph: Adrian Wyld/AP

“We cannot allow that openness and freedom to be rolled back either,” he said.

The Liberal party leader, Justin Trudeau, said those who attack Canada “will not make the rules about this land we share and they will not get to change us”.

Harper acknowledged the strain that Wednesday’s events put on the capital, calling it “beyond and above anything that any of us are really expecting to face”.

But amid the determination and effort to return to normality, there was tight security in the downtown area – unusual for Ottawa. A security permitter around Parliament Hill meant that only a small number of staffers, parliamentarians and journalists were permitted through, and only at one checkpoint. Cordoned-off streets meant a headache for commuters.

Despite the contentious debate on how to respond to the threat of domestic terrorism, the political parties were unified in their tribute to the sergeant-at-arms, Kevin Vickers, who was given a prolonged standing ovation at the opening of the parliamentary session.

But Vickers was keen to praise his colleagues. “During extraordinary circumstances, security personnel demonstrated professionalism and courage,” he said in a statement. “I am grateful and proud to be part of this team.”

Reports emerged on Thursday that Vickers, after killing the shooter, rushed to a nearby room, where the Harper was meeting with his caucus, to ensure the prime minister’s security.