The West Midlands has to fight to keep hold of its Eastern European immigrants, if it wants combat the threat of an ageing population, a senior European Commission official has said.

Charles White, principal administrator for regional policy at the European Commission, said the region needed to encourage workers from countries such as Poland and Slovakia if it wanted to see continued economic growth.

Mr White said: "It is inevitable that if the indigenous population declines there has to be something to fund the economic gap.

"The West Midlands migrant economy is making a big economic contribution and more needs to be done with regards to social integration if they are going to stay.

"They have to be allowed to train in the UK and undertake useful careers."

By 2050, it is estimated that the number of Europeans over the age of 60 will have doubled to 40 per cent of the total population - or 60 per cent of the working age population.

With more people entering retirement there will be a greater pressure on health-care, pensions, housing, and community care. Yet with birth rates across Europe falling, there will be fewer younger people to drive the economy and pick up the growing welfare and social bills.

According to the West Midlands Observatory, in 2005 there were 3.2 working adults to every pensioner in the region. This compared to 3.4 working adults ten years earlier.

The trend is also set to continue. Figures by Age Concern suggest the West Midlands will have almost 400,000 more people over the age of 65 years by 2028, whereas the number of 15 to 45 year-olds - the key working age group - will drop by 126,300.

But despite this, the West Midlands has so fared better than many other European cities because of its ability to attract immigrants.

But, Mr White said, simply attracting them may not be enough.

He said: "If I was a UK resident I would be hoping that all those lovely young Poles would stay and help me in my retirement.

"What the region needs to do is integrate them into local life and encourage them to stay and have families.

"We need to encourage them to stand for councils get them involved in local politics - make them realise that the country under-stands what they think.

"That is not to say that we should try set up a Polish-speaking council, they would have to learn English.

"Eastern European immigrants are contributing economically and many have a awful lot of political energy that the UK should be engaging."

But, if the region wants to keep hold of young workers coming from the EU's newest states, it has a fight on its hands.

While the whole of Europe has seen declining birth rates, the UK - along with western Germany, eastern Austria, Spain and Greece - has been boosting its population by immigration.

But the population decline in north-eastern European countries - including Poland, Slovakia and Hungary - is being made worse because of emigration.

This is such a concern to the European Commission, that one of the priorities for structural funding budgets - the money used to help try to bring EU countries in line economically - will be to support projects that stop this population decline.

With the accession states receiving the largest structural budgets for 2007 to 2013 - the UK can expect competition as they try to encourage their young workers back home.

Mr White said: "Ireland is an example of what can be done with European funding.

"Many Irish people had left their country to find work abroad, but now they are coming back. That isn't because we've been keeping them out of everywhere else, we did it by turning Ireland into the richest little country in Europe.

"Eastern European people don't want to stay abroad, they want to go back home and the EU has to provide the opportunity for them to do that."

Mr White added that the West Midlands needed to be creative with the way that it addressed the issue of ageing.

He said: "If you look at the ageing population as a problem, then it is enormous - especially with pensions failing and people living for a lot longer.

"But the European Union has got projects that demonstrate that it is a real opportunity as well."

In Liege, Belgium, there is a problem with unemployment and also a lack of day-care for the elderly. If you keep them separate then it's like a bucket of bad apples - they all go off. Mix them them together and suddenly the old people freshen up laughing with young single mothers and telling them stories about what they got up to in the war years.

"The younger people stop feeling so isolated and alone and they start to develop a sense of responsibility.

"It can also be a business opportunity - there will be opportunities in care and other sectors.

"If businesses in the West Midlands don't think a bit laterally and approach ageing as a problem, they will miss out."