The Department of the Environment had strongly opposed these new link roads, which will first be built beside the busiest section of the M25 running between the M3 and M4 west of London. Local Tory MPs, councils and green groups continue to oppose them.
Mr MacGregor said there would be a public inquiry next year into the first link roads. Three lanes wide and nearly eight miles long, they are intended to remove traffic travelling between the M3 (Junction 12) and the M4 (Junction 15) from the M25, which carries up to 200,000 vehicles a day on that stretch and slows to a crawl for one hour in 24.
The two link roads will cost pounds 144m. Mr MacGregor hopes they will be completed by about 1998.
He also announced plans for two-lane link roads between the M4 north to the M40 (Junction 16). Public consultation now begins on these latest link proposals which will be five miles long and cost pounds 52m.
The entire M25 is eventually to be widened from dual three lanes to at least dual four lanes. Mr MacGregor made clear that nearly one-third of the motorway will probably have to be wider still in order to cope with traffic growth. North-west and south-west of London, from the M1 (Junction 21) to the A3 (Junction 10), the M25 may require either dual five lanes or link roads. There is also the possibility of widening beyond four lanes east of London.
Mr MacGregor said the remaining 70 per cent of the M25 would not be widened beyond dual four lanes, but that could only be guaranteed until 2015. After then, electronic tolling systems might be used to clamp down on the growth in traffic.
More and more traffic is leaving the M25's most congested stretches and using roads through towns, villages and outer London suburbs. Mr MacGregor pointed out that the AA had recently published a guide to these off-motorway rat runs. 'Doing nothing is not an option,' he said. 'It is essential for our industry and commerce that the M25 should work effectively.' Earth embankments will screen the link roads and hundreds of thousands of trees and shrubs will be planted.
Peter Ainsworth, Tory MP for East Surrey, said: 'The link roads plan is not a medium-term or a long-term solution to the problem of traffic growth. There's very strong local opposition and it's going to be a lively public inquiry.'
Environmentalists condemned the scheme for the increased air pollution, traffic noise and loss of countryside it will bring.