Outer London has seen rising levels of poverty while the number of poorer areas in central London is reducing, according to a new analysis of official deprivation data.

Although the poorest places in the capital are still in the eastern centre of the city, there are fears that poverty is being pushed out into the suburbs amid evidence of a significant increase in deprived areas in the outer boroughs between 2004 and 2010.

The findings are also acute in areas that saw rioting last August. In Enfield and Haringey, 22 neighbourhoods have become more deprived; in Ealing and Hillingdon 33 have and in Croydon and Sutton 75 have. Only 20 neighbourhoods in those three London assembly areas have become less deprived.

The figures were on the rise before the 2008 mayoral election. Boris Johnson won after focusing his campaign on the outer London ring in a "doughnut strategy". He beat Ken Livingstone by fewer than 140,000 votes, while the Labour candidate's core vote strategy centred on the inner city. This time around, he may face hostility from voters who have seen living standards decline.

The data shows that 430 neighbourhoods in London have become significantly more deprived than their neighbours since 2004, and 400 of those are in the outer boroughs.

In contrast, only 374 neighbourhoods across London have become significantly less deprived, and they are predominantly in the west and central parts of the city.

The biggest contrast is in the Brent and Harrow London assembly area, where 83 areas have got more deprived and only one has become less so. The data measures poverty in tiny "lower super output areas", each with a population of around 1,500 people. An area that has slipped down the index and become more deprived may still not be poor – it has just become more deprived compared with other neighbourhoods.

Tony Travers, director of the Greater London group at the London School of Economics, said: "It would appear that in 2008, rising levels of deprivation were associated with voting for Boris Johnson. It is paradoxical that as outer London has got poorer, it has appeared to vote for Johnson. Ken Livingstone will no doubt be hoping to reverse this with his policies in 2012."

The poverty data is based on an analysis by Alasdair Rae at the University of Sheffield of the government's Indices of Multiple Deprivation, which measures relative poverty across England, between 2004 and 2010. Rae said: "In London, it would appear that centrifugal forces are currently helping shift poverty from inner to outer London."

A recent report by the London School of Economics found that a majority of people in poverty in London now live in the outer city, whereas a decade earlier it was evenly split.

This reflects what is happening in major US cities, where a Brookings Institution report found the suburbs were home to the largest and fastest-growing poor populations in the country.