The City Corporation says that the Home Office fully supports the cordon, which has meant eight checkpoints and the closure of 18 roads.
The move is a response to the bombings at Bishopsgate on 24 April and St Mary Axe, a year previously, which caused huge devastation to the financial centre. But the Department of Transport has indicated that it does not want the road closures to become permanent. Steven Norris, the transport minister for London, has serious doubts about the scheme, believing that its effectiveness as an anti-terrorism measure is questionable.
Mr Norris said last week that sealing off the centre of Belfast had been a 20-year failure, and to attempt something similar in London was a propaganda coup for the IRA. Mr Norris told the Independent on Sunday that his thoughts were 'very private views expressed more in sorrow than in anger'. But other DoT ministers have also said privately that the closure is a 'dotty idea' which can be seen as caving in to the bombers.
The department, which was given only two days' warning about the cordon, would need to give formal permission if it were to become permanent. Under road traffic regulations, roads can be kept closed for up to six months and the closure then renewed for a further six months.
The corporation has said privately that it had no choice but to introduce a very visible anti-terrorism measure after pressure from Eddie George, governor of the Bank of England and Lord Alexander of Weedon, chairman of National Westminster Bank.
A senior corporation officer said: 'In the short term we had no alternative. Call it window-dressing but at least something was being done. Although it can't be the long-term solution, it may be that out of this will come the environmental benefits which are needed.'
The three London boroughs bordering the City have joined in protest over the cordon. Tower Hamlets has delivered a written protest to the Government, registering its fury over the 'complete lack of consultation'. Islington, which first heard of the plan by fax the night before it was implemented, is co-ordinating opposition through the Association of London Authorities. Southwark, on the southern borders of the City, has sent a strongly-worded letter to the corporation expressing its 'regret over the total lack of consultation', while pledging to support Tower Hamlets' protest to the Government.
'We were angry, not to say furious, at the way these closures were introduced,' said a spokesman for Tower Hamlets. 'We appreciate that the City has been a major terrorist target twice, but if you force terrorists out of the area, what is to stop them just moving down the road? There has already been one attempt to bomb Canary Wharf.'
He said the City was committed to the long-term pedestrianisation of the area. 'However, when it comes to transport policy, the City has always completely ignored the knock-on effect on the neighbouring boroughs.'
Although none of the boroughs reported any significant rise in traffic disruption, they are closely monitoring the situation on a daily basis.