People angry over jobs cuts and the recession are expected to take to London's streets. [AFP]
Police and security forces are gearing up for a day of protests before the G20 summit in London, with this year's demonstrations expected to contain a new, angrier, element.
For building contractors suffering as a result of the current economic squeeze, the G20 summit has been good for business.
The City of London, the square mile that marks the financial centre of the capital, has been a hive of activity over the past week.
Builders have moved in to board-up shopfronts and protect doors and windows from the expected arrival of thousands of protesters.
This G20 is proving to be an epic summit, and not just because of the sheer scale of the problem the world leaders are trying to solve.
The security operation, which according to some estimates will cost up to of $30m, will see London transformed into one of the most heavily guarded cities on the planet.
There will be 84,000 police "man-hours" devoted to Operation Glencoe, which will rely upon six separate police forces, drawing in officers from the regions surrounding London.
The location of the G20 meeting itself, the ExCel centre in the east of the city, will apparently be a "sterile" zone.
The venue is considered highly secure, with water on one side that are patrolled by the police with marine launches.
Checkpoints and other cordons will also be in place and once opened, the focus will turn to protecting the delegates' journeys in and out of the centre.
But beyond this area the city could become a battleground, with thousands of protesters facing off against the extensive security apparatus.
The biggest protest is planned for Wednesday, the day before the actual summit.
There is a veritable feast of marches planned, representing just about every lobby group imaginable and they will not be confined to one area.
The groups range from "Youth March for Jobs" and "Jobs not Bombs" to "Climate Camp".
All of them are anti-establishment and many of them have spent years being branded by the media and politicians as "the lunatic fringe".
"This will not be your bog-standard day of anti-globalisation protest action"
Al Jazeera correspondent
But times have changed and suddenly these activists are feeling vindicated.
Many of those protesting feel that the spiralling global economic crisis has given them the right to say "we told you so!".
This will not be your bog-standard day of anti-globalisation protest action because suddenly the people holding the banners do not just represent themselves and a small band of academic elite, they represent those thousands of people losing jobs, losing homes and losing faith in the system.
A few pin-striped bankers, or at least recently unemployed bankers, are also expected to take to the streets, with placards in their hands.
In total, up to 100,000 protesters are expected to turn up on Wednesday.
The biggest potential flash point seems likely to be outside the Bank of England, where three or four separate marches are expected to converge around lunchtime.
In casual clothes
Staff working in the financial sector surrounding the central bank have been told to turn up to work in casual clothes instead of their usual suits.
They have been encouraged to bring a packed lunch, not to book outside meetings and alter their travel times in a bid to avoid the angry mobs.
There seems to be a sense that widespread violence during these protests is inevitable, but that may not be the case.
Both the police and the protesters are demonstrating immense organisational skills, which could keep the day under control.
Either way, the demonstrations will be big and loud, and people will take notice.
Perhaps this time their calls won't be ignored.
Source: Al Jazeera