Visitors to the House of Commons will have to sit behind a bullet-proof screen to watch the debates from the famous visitors' gallery, it was reported last night.
The screen has been recommended as part of a review of Commons security, predating the recent incident in which a group of anti-war demonstrators disrupted Prime Minister Tony Blair's speech on the Hutton report, forcing the Speaker to order all visitors out of the gallery.
The last time anyone threw anything down from the gallery on to MPs below was 25 years ago, when protestors threw animal manure
Since then, security barriers and metal detectors have been introduced at every entrance, but House of Commons authorities are reputedly worried that a determined terrorist might get plastic or liquid explosives past the screening procedure, according to today's Sunday Times.
More recently, concrete anti-tank blockades were installed, and armed police brought in for guard duty.
Contractors have begun work on fortifying the chamber, and are due to finish in mid-April.
The MPs' Easter break has been extended by a week to allow time for the work to be completed.
A Commons spokesman declined to comment on the report, saying: "We never comment on security matters."