Heathrow Airport's Europa Building (later to be re-named Terminal 2) departures hall in 1965

Completion of major structural work at Heathrow’s new £2.5 billion Terminal 2 will be marked with a topping-out ceremony at the London airport today.

An artist's impression of how the new Terminal 2 at Heathrow Airport will look

The new terminal, which will be capable of handling 20 million passengers a year, is part of a £4.3bin package of work.

To minimise disruption to passengers, construction of T2 is taking place in two phases. The first phase, to open in 2014, sees the creation of the main terminal on the site of the old Terminal 2 and Queen’s Building.

It also involves the construction of a satellite terminal with additional aircraft parking stands and passenger gates called Terminal 2B.

The second phase will extend the main Terminal 2 building northwards onto the existing Terminal 1 site.

This phase, which will also include the construction of a second satellite building, T2C, will increase the capacity of Terminal 2 from 20 million passengers a year to 30 million passengers a year.

Opened in 1955, the old T2 shut in 2009 and was demolished in 2010.

It was Heathrow’s first terminal, originally called the Europe Building.

Originally designed to deal with 1.2 million passengers a year, it was dealing with eight million annually when it closed.

Colin Matthews, chief executive of Heathrow’s operator BAA, said: “Terminal 5 (at Heathrow) set a new standard for airport terminals. The completion of structural work on Terminal 2 puts us within touching distance of a future where Heathrow has some of the best passenger facilities in Europe.

“There’s a lot still to do, but the opening of Terminal 2 could move Heathrow into pole position among European hub airports and allow us to set our sights on elite airports such as Singapore, Hong Kong and Incheon in Seoul (South Korea)”

Transport secretary Justine Greening said: “For tens of millions of people each year Heathrow is their first impression of the UK, which is why it is so important that it is a positive one.

“We have been clear that we want to improve the experience of those travelling through our airports, and this new terminal will do just that.

“This is also a success story for the country’s construction industry, with British-made steel, electronics and engineering responsible for a state-of-the-art facility.”