A baby boom has fuelled a record increase in the population with the number of people living in the UK topping 61 million for the first time.

Fertility rates have hit their highest level in more than 30 years, according to the Office for National Statistics.

In the West Midlands the fertility rate was above the national average. A total of 71,726 babies were born in the region alone, bringing the total population to 5.4 million.

Nationally, more than three quarters of a million children were born last year, fuelling the biggest year-on-year rise in the population since the 1960s.

The peak was reached despite an apparent end to the vast wave of Eastern European immigration of recent years.

Figures from the Office for National Statistics (ONS) confirmed the recession-linked decline in immigration, as tens of thousands of Eastern Europeans returned home and the number of new arrivals plummeted.

For the first time in nearly a decade birth and death rates overtook immigration as the biggest factor affecting population growth.

But immigrants were still contributing to the population increase – half of the year-on-year rise in births last year were to women born outside the UK.

The total population is now 61.4 million, up more than 400,000 in a year and a rise of more than two million since 2001.

ONS statistician Roma Chappell said: “It’s the highest fertility rate we have seen in the UK for some time.

“You have to go all the way back to 1973 to find a time when the fertility rate went higher.

“For the first time in a decade natural change exceeded net migration as the main driver of population change.”

The number of arrivals from the eight Eastern European countries which joined the EU in May 2004 reduced to a trickle as the economy nose-dived, the figures showed.

In the year to December it fell more than a quarter from 109,000 to 79,000.

More Eastern European immigrants went home in the same period – up by more than 50 per cent to 66,000.

The Government’s critics said the population was still on course to hit 70 million within the next 25 years, and they accused Home Secretary Alan Johnson of “sleeping on the job”.

But Immigration Minister Phil Woolas said: “The fall in net migration is further proof that migrants come to the UK for short periods of time, work, contribute to the economy and then return home.”

Dalia Ben-Galim, senior research fellow in social policy at the Institute for Public Policy Research, said the boom will expand the “sandwich generation” – people who care for their own parents and children.

“One of the pressure points is increasing the numbers of people with multiple responsibilities, and there will be more four generation families, where grandparents will be caring for children and their own parents,” she said “This will lead to more pressure for flexible working, allowances for carers and so on.”

With an ageing population, there would be more pressure on carers as a lot of people would live longer, through periods of poor health and disability.