A think group has declared that the decline in productivity and living standards in the UK has been "exceptionally bad," notwithstanding the country's immigration growth.

According to the Resolution Foundation, there have been 4,500,000 million inbound migrants to Britain since 2010, making it the nation with the highest population growth in a century.

The organization's study indicates that the UK's GDP has grown by just 4.3% over the last 16 years, while it increased by 46% over the 16 years prior.

Greg Thwaites, research director at the Resolution Foundation, told the Telegraph: "Britain's middling growth record has been propped up by a booming population.

"The extra six million people in Britain have certainly made the economy bigger but has done little for GDP per capita. In fact, the UK's record on productivity - which is what really matters for living standards - is exceptionally bad."

Further analysis from the group said average annual productivity had a growth of 0.4 percent over the past 16 years, which it said was the slowest rise in 200 years. The average living wage was over £14,000 below the beginning of this trend the foundation found.

Mr Thwaites added: "There is widespread consensus on the need to turn around the UK's productivity record, which is far easier to talk about than deliver."

During an election campaign appearance on a BBC debate with her rivals, Conservative Cabinet minister Penny Mordaunt told the audience "Immigration is too high."

On reducing immigration, she said: "The best way to do this is to get Parliament - your parliament, elected by you - to have an annual cap.

"What that will do is take into account the economic needs, the needs of the workforce, but also the pressures that immigration puts on communities."

Labour deputy leader Angela Rayner replied: "The problems with housing, the roads and the GPs and public services is decimation the Tories have done to our public services."

Ms Mordaunt interjected: "Your leader (Sir Keir Starmer) campaigned for free movement."

Ms Rayner continued: "We would scrap the Rwanda scheme. We would put that money into a Border Force Command which would be able to smash the gangs because we need to do that.

"And 14 years of the Conservatives, they're relying on overseas to fill our skills shortages because we haven't got an industrial and skills strategy."

In the background, Ms Mordaunt said: "We've got one in place."