With the government issuing a three-line whip to its MPs - meaning they have been ordered to vote in favour - it is widely expected that the expansion plan will get Commons backing.
Up to 40 of Labour MPs are expected to vote for the plan, which is also backed by leading trade unions.
Opponents of Heathrow expansion have attacked the scheme on environmental, noise and financial grounds, with some making the case for an alternative expansion scheme at Gatwick airport.
Even if lawmakers approve the plan, it could still face a legal challenge from a group of local councils, and last week, the Mayor of London Sadiq Khan said he would join the action against the third runway if parliament voted to approve it.
Heathrow is Europe’s busiest airport but is now operating at full capacity. A 14 billion pound ($18.6 billion) plan to build a third runway faces opposition from local communities and environmentalists, but its backers say it is needed to enable new trade links and help secure economic growth.
The decision to expand Heathrow follows almost half a century of indecision on how and where to add new airport capacity in densely populated southeast England. If it goes ahead, it will be the first full-length runway built in the London area for 70 years.
