The latter stages attracted opposition from environmental campaigns across Britain due to its large cutting through wooded Twyford Down; numerous road protests were held which delayed its opening.

Since completion, the motorway has been an artery to the west and midsections of the South Coast and Isle of Wight including for tourism.

From Chertsey to Fleet the road was in 2017 converted to a Smart Motorway, turning the hard shoulder into a permanent fourth lane with emergency refuge lay-bys.

A first public inquiry for the "M3 London to Basingstoke Motorway: Popham to Compton extension" centred on the section passing Winchester, and was held in 1971, after which the ministry was instructed to reconsider and reconsult on the proposals.

[8][9] The earlier decision to route the motorway through or alongside the water meadows between St Catherine's Hill and the compact cathedral city was reopened, and during the year-long inquiry the headmaster of Winchester College was forcibly ejected along with others for causing a disturbance.

[citation needed] Plans for a Basingstoke Services were again published in November 2017[11] An additional junction, numbered 4A, was opened in April 1992 for Fleet.

From here the motorway continues as a dual two lane road through open countryside and Micheldever Wood until it reaches the north of Winchester.