Merseyside will lose 100,000 of its 1.4 million population by 2021, the Office for National Statistics said in its latest population report.

The north east will lose 100,000 of their 2.4 million population, while the south east is set to gain one million new residents, bringing the head count to 8.9 million in 2021.

The north/south house price is getting wider

Today's report has stirred fears that the north-south divide has re-emerged, fears already fuelled by the gap in house prices between north and south as well as unemployment data.

Evidence of a divide stems from recent unemployment figures. At 4.4% in June, the unemployment rate was at its lowest for 20 years, but regional differences exist. Unemployment in the south east was 2.5%, compared with 7.4% in the north east.

People who move south to look for high-skilled jobs appear to stand a better chance than those who confine their job search to the north.

In the south of England, 40% of workers have managerial or professional jobs, compared to 30% in the north, the CBI said.

That said, the chances of getting unskilled work in the north are improving, Adam Cole, UK economist at HSBC said.

Jobs on the move

Advances in technology have meant that service sector employment, traditionally concentrated in the south, has moved north where there is available labour.

"Technology has meant you don't need to be at the headquarters of a company to work for them. What is happening is that the jobs are moving to the people, rather than the people moving to the jobs," Cole said, adding that the gap between employment in the north and south is smaller than in the 1980s.

Some businesses welcome the fact that workers are prepared to up sticks and go where the jobs are.

"In essence we would say that the shift in Labour from the north to the south is quite useful. There are shortages of Labour in the south east of England. In Newbury and Reading, unemployment is virtually non-existant," the Institute of Directors said.

Indeed the move south can also be seen as generational, as young people perceive the opportunities of their home town as limited and choose to head to the big city.

For those who leave through need rather than choice, it is hard to see how the situation can be improved.

BoE governor George fuelled the debate

Some argue it is made worse by the use of one interest rate for divergent regional economies.

This view was lent support by Bank of England governor Eddie George's comments last year that unemployment in the north was a 'price worth paying' for keeping inflation in check.

If interest rates can't level the playing field, Regional Development Agencies should be able to help. Even these have their critics.

"What attracts companies to an area is not a government policy but the existence of a pool of available Labour," Cole said.

Few quick-fix solutions exist. It is, after all, a problem faced not just by Eddie George and Chancellor Gordon Brown, but also the European Central Bank, which has to set one interest rate for the countries participating in monetary union.

If the thousands forecast do migrate, the effect on transport and housing in the south east is difficult to calculate.

Can London's already beleaguered transport system cope with another million users?

"The Underground is operating at capacity already," a London Transport spokesman said.