Nearly half a million households in the UK are still in negative equity - meaning the houses are now worth less than the amount owners borrowed to buy them , figures show.

This is a decrease to 463,415 (8%) households from the 826,800 (14%) households recorded in the first quarter of 2011 - but this reduction "masks huge regional variations".

At the top of the table were the 41% of borrowers in Northern Ireland - 68,024 households - in negative equity at the end of 2013, the figures from mortgage group HML show.

It is thought Northern Ireland is still suffering in the aftermath of the Celtic Tiger property boom years.

Meanwhile, the north/south divide in England is " alive and well", the director of business intelligence at HML, Damian Riley, said.

The figure for Greater London is just 5,942 households (1%), while the South East and South West are 2% and 4% respectively.

Around 86,000 households in the North (16%) and North West (7%) are in negative equity.

In Scotland 72,845 (13%) of borrowers are in negative equity, with the "unresolved issue of sovereignty" suggested as the main reason.

In Wales 12,258 (4%) of households are in negative equity.

The figures are based on mortgages taken out since 2005.

Mr Riley said: "Clearly, the overall reduction in UK negative equity between Q1 2011 and Q4 2013 masks huge regional variations - it appears the north/south divide is alive and well where negative equity is concerned.

"Hopefully, the expected London-centric ripple effect regarding house price recovery will take hold and the more distant provinces will play catch-up over the coming months and years.

"In Scotland, the unresolved issue of sovereignty could be the leading reason for the continuing depression in property prices; resolution is expected following the independence referendum.

"In Northern Ireland, contagion from the bursting of the Celtic Tiger property bubble may take much longer to resolve."

He added: "While the UK housing market is in general recovery, at regional and local level the view remains mixed. Doing nothing is an option; after all, unless a homeowner wants or needs to sell, the issue of negative equity is of low relevance, and over time improving house prices may kill off the issue for many.

"However, if homeowners have free disposable income, making overpayments now to help decrease any negative equity gaps, particularly before a mortgage interest rate increase, would be a very sensible course of action.

"Lenders may also want to be more flexible with the terms and conditions placed on mortgages, allowing customers to overpay without facing fines."