A former Cabinet minister has called for all parliamentary security procedures to be reviewed following a series of shootings in Canada. House of Commons officials said the authorities "remain vigilant" and are monitoring the situation in Ottawa, where a gunman shot dead a soldier at a war memorial before running into the parliament and firing further shots.
Shots were also fired at a shopping centre in the capital and armed police are searching for other suspects. Prime Minister David Cameron offered his support to Canadian counterpart Stephen Harper as he condemned the attacks. He tweeted: "I'm appalled by today's attack in Ottawa. I offer my full support to @pmharper and the Canadian people as they deal with this incident."
Peter Hain, who introduced tougher security measures as Commons leader in 2004 following a series of breaches in the chamber, said it would be "prudent to review everything" following the Canadian attacks. The former Northern Ireland Secretary said: "I'm sure the head of security will now be urgently reviewing our procedures.
"I think it would be prudent to review everything in light of Ottawa but I believe that our procedures are much more rigorous than in 2004 when security was a joke."
Parliament's security procedures were criticised intensely at the time when protest group Fathers 4 Justice threw a condom containing purple powder at then-prime minister Tony Blair in the Commons chamber and pro-hunt campaigners, including rock star Bryan Ferry's son Otis, stormed in during the hunting ban debate.
Earlier today, a man was taken into police custody after apparently throwing marbles at the glass screen covering the public gallery in the House of Commons during Prime Minister's Questions. A bang was audible in the Commons chamber as David Cameron took questions during the weekly session, but the incident did not disrupt proceedings.
The Serjeant at Arms, who wears a traditional uniform and a sword, is responsible for security in the House of Commons, but parliament now also has a security director who is responsible for safety across the whole estate. That role is currently held by former spy Paul Martin, who was an MI5 counter-intelligence expert.
A House of Commons spokesman said: "The security authorities at the Houses of Parliament are monitoring the developing situation in Ottawa. The authorities here remain vigilant, and measures appropriate to the current threat level in the UK continue to be taken on the parliamentary estate."