LONDON (Reuters) - The British government dismissed speculation yesterday it was about to roll back on a levy on wealthy foreigners who have so far been able to legally avoid paying UK tax.

Finance minister Alistair Darling had announced a plan in October to give non-domiciled individuals living in Britain the choice — after seven years — of either paying an annual £30,000 levy or to fall under the UK tax system.

Pressure has grown on Darling to backtrack on the plan in his first budget next month given comments by trade minister Digby Jones that such a policy would drive away investment.

"The government's policy remains as it was set out in the pre-budget report," a Treasury spokesman told Reuters. "The final legislation will reflect the government's intentions that were set out."

In a letter of clarification to tax advisers, acting chairman of Revenue and Customs Dave Hartnett said the reforms would maintain "the competitiveness of the UK as a place to work and do business".

Hartnett said individuals who want to pay the £30,000 — and continue only paying tax on foreign income when they bring it into Britain — will not need to disclose any information on the source of those remittances.

He also said the tax changes will not be applied retrospectively.

"There are issues of fairness, which need to be addressed," Hartnett said in the letter. "First, the fact that people can be resident in the UK over the long term without making any contribution in respect of income they leave abroad."