The annual Sunday Times Rich List says the United Kingdom's richest people have defied the double-dip recession to become even richer over the past year.

The paper says its research showed the UK's richest people have increased their wealth by 5 per cent.

The top 1,000 people on the list now have a combined wealth of more than $640 billion.

The list's compiler, Philip Beresford, says the entrepreneurs have a duty to put their money to good use.

"What we need from them now are the jobs and investments that come from those profits so that we all rise on a rising tide of prosperity," he said.

For the eighth year in a row, steel tycoon Lakshmi Mittal holds the top spot with a personal wealth of about $20 billion.