LONDON – Britain’s government is expected Tuesday to back a plan to expand London’s Heathrow airport despite concerns about air pollution, noise and the destruction of homes in the capital’s densely populated western neighbourhoods.

Transport Secretary Chris Grayling will inform Parliament of the government’s decision on how to expand London’s airport capacity. The options include building a third runway at Heathrow, extending an existing runway there, or building a second runway at Gatwick Airport, south of London.

The decision is only the first step, though. The government’s recommendation will be studied further and Parliament will vote in about a year.

Most analysts expect the government to back one of the Heathrow options.

Anti-expansion groups gathered in the village of Harmondsworth, near Heathrow and in Crawley, near Gatwick, to await the news. Neil Keveran has campaigned against Heathrow expansion for years and plans to fight on – even if the government goes for the third runway.

“A monopoly at Heathrow will serve nobody,” he said. “It won’t be good for passengers, it won’t be good for other regional airports. I don’t believe the runway will be delivered. I think legal challenges, and if necessary direct action, will prevent the growth of Heathrow.”

London and southeastern England need more airport capacity to meet the growing demands of business travellers and tourists. Heathrow and rival Gatwick, 50 kilometres south of central London, have offered competing projects that will cost as much as 18.6 billion pounds ($29.1 billion). Whichever proposal is selected, homes will be destroyed and surviving neighbourhoods will have to cope with increased noise, pollution and traffic.

The issue was so toxic that politicians created an independent commission to weigh the options – and it decided to expand Heathrow. But it is up to political leaders to make the final decision, and authorities have stalled. The upheaval prompted by Britain’s vote to leave the European Union pushed the issue back further.

A furious public relations battle has raged, with placards all over London’s subway system, for example, extolling the virtues of Heathrow or Gatwick. The commission has already rejected other options, such as one backed by former London Mayor Boris Johnson to build a new airport in the Thames Estuary.

John Allan, chairman of London First, which campaigns to make the capital business-friendly, told the BBC that the government needed to make up its mind.

“What we want above all is more airport capacity in the southeast,” he said. “The most important thing is to get on with it. Even though it is only a step in the road, it is a very important step in the road.”