London's Big Ben will ring in the United Kingdom's new year with a fresh face, two years after restoration works began in 2017.

Key points: Big Ben's clockface has been restored to its original colours

Big Ben's clockface has been restored to its original colours The work on the clock tower is the first phase of extensive restorations at the Palace of Westminster

The work on the clock tower is the first phase of extensive restorations at the Palace of Westminster British MPs will have to move to a temporary parliament while the work is carried out

Big Ben is the colloquial term for the bell located within the 96-metre Gothic Elizabeth Tower that adorns London's Palace of Westminster.

The tower has been seen through scaffolding for the past two years, during the first of many restoration works that will bring the world heritage-listed Palace of Westminster in line with 21st-century building codes.

New year, new look

Since restoration works began the tower has had its four clock dials reglazed, ironwork repainted and intricately carved stonework cleaned and repaired.

A restorer places gold leaf on the roof of Elizabeth Tower. ( Reuters via UK Parliament / Jessica Taylor )

In March part of the scaffolding was removed, showing that the clock's once black numerals and hands have been repainted blue, in line with what scientists say was its original colour.

Big Ben has sat largely silent during the work, sounding only for important events.

The Big Ben bell has chimed across London since the middle of the 19th century. ( Reuters via UK Parliament / Jessica Taylor )

It last tolled on Remembrance Day on November 11.

The bell will be tested several times in the run-up to New Year's Eve, the UK Parliament said in a statement.

The complete restoration of the entire Elizabeth Tower, worth an estimated 61 million pounds ($114.4 million), will see it repaired and redecorated, including bringing colours back to the original design by 2021.

Renovation ushers in palace overhaul

The Palace of Westminster seen today dates back to the Victorian period. ( US Library of Congress via Picryl: GW Wilson )

The overhaul of the Elizabeth Tower forms one small part of multi-billion-dollar refurbishment of the Palace of Westminster, which is home to both British houses of parliament.

The crumbling palace carries layers of history that now pose grave risks for the building itself.

The Guardian reported in 2017 that the building caught fire 40 times between 2008 and 2012, while some of the pipes and cables running through the building date back to the 19th century.

The House of Commons website revealed the need for restoration works, noting "the building is deteriorating faster than it can be repaired".

"The longer this essential work is left, the greater the risk that the building will suffer a sudden catastrophic failure that makes the building uninhabitable and brings a sudden stop to the work of Parliament," it said.

The palace as it is today dates back to the middle of the 19th century.

It was rebuilt after fire destroyed the old palace, which dated back to the medieval period.

English, and later British, MPs have met on the site that the palace now occupies since at least the 13th century.

The site has been a witness to pivotal moments of English and global history, bearing witness to the English Civil War, German air raids during World War II, and the rise and fall of the British Empire.

Urgent restoration work prompted British MPs to vote for temporary relocation from the Palace of Westminster. ( Supplied: House of Commons Northern Estate Program )

In January 2018, British MPs voted to leave the palace to allow "increasingly urgent" restoration works to take place.

All 650 House of Commons MPs and their staff will be relocated to a temporary parliament across the road from the palace in a cluster of old and modern buildings known as the Northern Estate.

Representatives from the House of Lords will be relocated to the Queen Elizabeth II Centre opposite Westminster Abbey.

ABC/wires