The Queen will formally name the Royal Navy's biggest ever ship today, with whisky replacing the more traditional champagne at the ceremony.

She will smash a bottle of Islay malt whisky against the HMS Queen Elizabeth at the event at Rosyth Dockyard in Fife, where the 65,000-tonne aircraft carrier has been assembled and fitted out.

The Queen will be accompanied by the Duke of Edinburgh at the naming ceremony, a naval tradition dating back thousands of years which combines a celebration and a solemn blessing.

The naming of the warship comes five years after the first metal was cut on the vessel and 33 months after the first section entered the dry dock at Rosyth to begin being put together.

The ship and a second vessel, the under-construction HMS Prince of Wales, are the largest warships ever built for the Royal Navy.

HMS Queen Elizabeth is now structurally complete and ready to be floated out of her dock for the first time this month, shortly after being named by the Queen. Commissioning will take place in 2017 after fitting out and several months of sea trials.

The two ships are both termed Queen Elizabeth Class aircraft carriers and are being built by the Aircraft Carrier Alliance (ACA), a partnership of BAE Systems, Babcock, Thales and the Ministry of Defence. Overall, six shipyards around the UK - Appledore, Birkenhead, Govan, Portsmouth, Rosyth and Tyne - have been involved in building various parts of the carriers.

Those behind the project, which costs an estimated £6.2 billion overall, say the QE Class will be the centrepiece of Britain's naval capability.

Each 65,000-tonne aircraft carrier will provide the armed forces with a four-acre military operating base, which can be deployed worldwide, operating the F-35 Lightning II and a number of types of helicopter. They will be versatile enough to be used across the full spectrum of military activity, from war fighting to providing humanitarian aid and disaster relief.

The length of each ship is the equivalent of 28 London buses - almost three times the length of Buckingham Palace.

Each ship, which has a life expectancy of around 50 years, will be fitted out with more than three million metres of cable and it will have enough power to light up a small town.

HMS Queen Elizabeth will have 679 permanent crew and capacity for 1,600 crew members when fully operational.