THE population of Scotland is expected to grow to a record five and a half million people within the next ten years with the vast majority coming from immigration into the country.

The number of new arrivals is predicted to outstrip the number of Scots born by nine to one, with more than half coming from outside the UK.

However, the amount of new faces predicted to arrive falls well short of the Scottish Government's previous target, which Ministers said was needed to help care for the increasingly elderly population.

In the run-up to the independence referendum last year, former First Minister Alex Salmond said he wanted to increase Scotland’s net migration to around 24,000 a year.

But experts say far fewer will actually arrive compared to those leaving the country, with the numbers expected to balance at 9,000 international migrants coming to Scotland along with around 5,000 from the rest of the UK each year.

Details of the country's future population are contained in fresh figures from the National Records of Scotland (NRS) and the Office for National Statistics (ONS), which say that the the number of people living in Scotland will grow to six million before the turn of the century.

However, statisticians have downgrades their previous predictions for population growth, due to a falls in the number of babies being born and people arriving in the country.

Registrar General and NRS Chief Executive Tim Ellis said: “The latest population projections indicate that while Scotland’s population is expected to reach record levels for years to come, it is not projected to be quite as high as the previous set of projections suggested.

“Scotland’s population is projected to continue to rise into the future because although Scotland’s birth rate and inward net migration levels have recently fallen, they are still high by historic standards. Also people at older ages are expected to live longer.”

Experts predict that by 2039 there will be 800,000 Scots aged 75 or more, an 85 per cent increase over the 25 year period.

This will put pressure on pensions, with the number of Scots of pensionable age rising from 1.06 million today to 1.36 million, while the average age is expected to rise from 41 in 2014 to 45.

This means the dependency ratio – the ratio of people aged under 16 and of pensionable age and over, to those of working age – is projected to rise from around 58 dependants per 100 working population in 2014 to 67 per 100 in 2039.

Of the people arriving in the country, 57 per cent are expected to come from abroad 32 per cent will come from cross-border migration with the rest of the UK.

During the next decade the number of children aged under 16 is projected to increase by two per cent, from 0.91 to 0.93 million, before dropping back to 0.92 million by 2039.

A Scottish Government spokesman said: “Controlled and fair migration is essential to Scotland’s future, both in terms of contributing to sustainable economic growth and mitigating the effects of demographic change.

"We know Scotland has an ageing population so it is vital that we continue to attract the workers we need to grow our businesses and support economic recovery.

"These figures show just how important migrants are to Scotland’s demographic and economic growth.”

The number of people living in the UK overall is expected to rise by 4.4 million to reach 69 million in 2024, while an increase of just under 10 million is predicted over 25 years to reach 74.3 million in 2039.

The estimates prompted fresh scrutiny of ministers' attempts to reduce net migration to below 100,000 across the UK.

Lord Green, chairman of campaign group Migration Watch UK, said: "The prospect of nearly 10 million in 25 years underlines the huge impact on housing and public services, unless the Government succeeds in bringing net migration right down."

MPs Frank Field and Nicholas Soames, the co-chairmen of the cross-party Group on Balanced Migration, said the ONS projections "set out in stark terms the consequences of not reducing immigration to the UK".

They added: "It is not in the national interest to increase our population so rapidly. It is not of benefit to the existing residents of the UK. The country will become still more overcrowded and the housing crisis even worse."

Simon Ross, chief executive of charity Population Matters, said: "Our natural resources cannot sustain indefinitely the number of people in this country or on the planet.

"We are all affected adversely by the rapid population growth of recent decades - from pressures on housing and public services to the environment and climate change."