Archie Campbell looks at the what Monday's vote means for campaigners on both sides of the debate on airport capacity .

This week, after decades of wrangling and delay, MPs voted to approve controversial plans for a third runway at Heathrow.

Airport capacity has remained one of the thorniest issues in UK politics for several decades – and while emerging nations have expanded infrastructure at dizzying speed, the debate over a third runway at London’s Heathrow remains a symbol of successive failures from UK Governments on large national infrastructure projects.

The UK’s political system has not proved up to the challenge. Few policy questions have been subjected to such prolonged scrutiny, but for a powerful example of this particularly British inertia, look at the three years it took for the Davies Commission to conclude exactly what the Department for Transport had itself concluded some 8 years before.

Surprisingly, it is the current government, led by a Prime Minister who has a tendency to stall decisions, that has broken the deadlock. The politically contentious decision to press ahead with the £14 billion expansion of Heathrow will see flights increase from 480,000 to 740,000 per year, and the number of annual passengers served to 130 million.

While Theresa May is politically weak, she has responded to the growing urgency to demonstrate that in a post-Brexit environment, Britain is an outward looking nation, intent on trading with its global counterparts. Taking this bold step is meant as a clear statement from the Government – the UK is open for business.

Unsurprisingly, the Prime Minister has faced a backlash from MPs of all parties, environmental groups and local councils.

The Foreign Secretary’s last minute sojourn to Afghanistan filled the newspapers this week, while a less noticed absence for the important vote was the Chancellor of the Exchequer, Philip Hammond, whose constituency of Runnymede and Weybridge lies near Heathrow.

MPs who were present for the vote included Greg Hands – who resigned his ministerial post so he could stay faithful to his election pledge of opposing the third runway – and John McDonnell, the Shadow Chancellor, who made a typically impassioned speech from the backbenches, on behalf of his constituents in Hayes and Harlington.

While the Vote No Heathrow Campaign staged a protest in Central Lobby, it was Boris Johnson who suggested, in a letter to constituents, that Heathrow’s expansion plans may never take off. Serious doubts have been raised about the project’s affordability, environmental impact and increased charges – which currently add an average of £22 per passenger to a ticket – which will inevitably be picked up by passengers.

One certainty is that those who have bitterly opposed the expansion of Heathrow for so long will continue to do so - this week, four local councils, including two Conservative-run authorities, confirmed they would seek a judicial review of the proposals.

This week’s vote in the House of Commons represents a decisive moment for campaigns on either side of the debate, but the battle is certainly not over. Public affairs and communication professionals in favour of the third runway will need to continue to make the case that the project represents the most sensible and affordable way to tackle the UK’s airport capacity issues, while those against will need to raise doubts about the viability of the plans.

Far from this being the final hurdle, Monday’s vote represents the start of the next chapter in the 50 year debate over a new runway in the southeast.