London - Net migration to Britain in the year after the Brexit vote fell by record levels as fewer EU nationals arrived and more left, according to official figures.

The estimate, which measures the difference between the number of people arriving and departing the country for at least a year, counted 230,000 net immigrants in the 12 months to the end of June 2017.

This represented an annual net decrease of 106,000 -- around a third -- with three-quarters of the fall due to a drop in the net migration of EU citizens.

It is the first full year-on-year estimate since Britain voted to leave the European Union in June 2016, with critics claiming it showed a so-called "Brexodus" is underway.

The figures showed 80,000 fewer people came to Britain and 26,000 more left than in the previous year, according to the Office of National Statistics (ONS) report.

"This 106,000 difference was statistically significant and was the largest annual decrease recorded," the ONS noted on Thursday.

Overall 572,000 people arrived in Britain, while 342,000 emigrated, in the year studied.

"Britain was attracting some of the most talented and hard-working people in the international labour market but now we are seeing clear signs of a Brexodus," said lawmaker Ed Davey, a home affairs spokesperson for the opposition Liberal Democrats party.

However Nicola White, head of international migration statistics at the ONS, wrote in the report that it is "too early" to tell if the decline "represents a long-term trend".

"These changes suggest that Brexit is likely to be a factor in people's decision to move to or from the UK –- but decisions to migrate are complex and other factors are also going to be influencing the figures," she wrote.

Theresa May's Conservative Party, currently in power without a parliamentary majority, has long pledged to reduce annual net migration to "tens of thousands".

A spokesman for the prime minister said the figures showed "progress has been made in that direction", while stressing "the continuing contribution" immigration makes to Britain.

He downplayed the significance of EU citizens in the fall.

"It's quite clear that EU nationals are still arriving in the UK and are still making a significant contribution here."