The Queen has officially opened Heathrow’s new Terminal 5 in a ceremony with 800 invited guests.

The £4.3bn terminal is set to begin operating on March 27 and will cater for up to 30 million passengers a year.

The Queen, who was accompanied by the Duke of Edinburgh, declared the terminal ready for business.

She praised the “bright, airy space and clean, efficient layout”.

“It gives me great pleasure to open Terminal 5 – this 21st century gateway to Britain and, to us, the wider world,” she said.

BAA chairman Sir Nigel Rudd said: “Terminal 5 marks the start of a new beginning for Heathrow, for BAA and for our millions of passengers. It is, by any standard, a triumph of ambition, commitment and collaboration.”

“It will breathe new life into Heathrow, allowing us to continue our transformation of the rest of the airport, and will put Heathrow and BAA back where they belong – at the leading edge of global travel.”

Hundreds of airport stuff and construction workers attended the launch, where a specially-commissioned piece of music was performed by a choir.

The opening follows a major security alert at the airport on Thursday, as a man with a rucksack ran onto the north runway.