The £172m project, stretching for almost two miles into the Cheshire countryside, is expected to increase capacity from 18m passengers a year to more than 40m by 2016.
With demand for air travel set to grow rapidly, it is certain to intensify the debate over where to build new runways and terminals elsewhere - particularly in the overcrowded south-east.
Backed by north-west MPs, publicly owned Manchester is pressing for better south-north transport links to take the strain off greater London. But much depends on a detailed government review of air transport, likely to come in a white paper after the election.
Ministers are acutely aware of the political sensitivity of the issue, with Conservatives already identifying unrelenting growth in the south- east, particularly plans for hundreds of thousands of new homes - and a deteriorating quality of life in the region as a key election issue.
The findings from the lengthy planning inquiry into the case for a fifth terminal at Heathrow are now due to be in the hands of ministers although a decision is unlikely before the election. Nationally, government forecasts point to a doubling of traffic over the next 15 years with passenger volumes at British airports likely to rise to 333m in 2015 and to more than 400m by 2020.
Any attempt by BAA, operator of Heathrow, Gatwick and Stansted, to further expand south-east airports - or develop new ones, such as Alconbury in Cambridgeshire - will run into strong opposition from environmental groups, Conservatives and local councils.
But business organisations, such as the London Chamber of Commerce and Industry, have urged ministers to bite the bullet and accept that fudging could seriously undermine Heathrow's position as the fourth busiest in the world. The chamber says runway capacity at all three London airports will be exhausted within 10 years.
But Manchester Airport plc, owned by the 10 councils in Greater Manchester, is urging the government to adopt an alternative strategy - based on expansion in the Midlands and the north, where growing airports could provide a considerable boost to flagging local economies.
It already owns Humberside airport and is poised to buy from the National Express group the fast-expanding East Midlands airport, which is vying with Stansted as the country's largest cargo airport. It has also set its sights on Newcastle airport and, being likely to buy Bournemouth airport, the company is poised to rival privatised BAA as Britain's second largest airport operator.
Geoff Muirhead, chief executive of Manchester Airport, said it was preparing to overtake Gatwick as Britain's second-biggest airport by 2012. "Millions of people travel to London for flights and millions from the north-west fly down to London [for them]. We have to grab those people and make direct flights from Manchester our priority."
