Theresa May is reportedly expected to order civil servants to investigate what more can be done to toughen the rules around student visas in a bid to reduce net migration to the UK. The reports come as it is still unclear whether the new prime minister will stick with predecessor David Cameron's pledge to slash immigration to "tens of thousands".

Home Office and Department for Education officials are "likely" to be tasked with the policy review, according to government sources quoted by The Daily Telegraph. The mandarins may reportedly explore making it harder for foreign students to be granted visas if they apply for courses at "low ranking" institutions.

The immigration issue dominated the EU referendum, with Vote Leave campaigners, including Foreign Secretary Boris Johnson, committing to an Australian-style points system.

May, as home secretary, had overseen the government's failure to meet Cameron's net migration target, with the figure hitting 333,000 in 2015.

But Nick Timothy, a close aide to May, warned in 2015 that it was "almost impossible" to achieve the target because of the "generosity" of the UK's student visa system.

"It is well known that the Home Office would like to reform the student visa system further, reduce the number of work permits issued to foreign workers, change the way the asylum system works, and win greater control of immigration from other EU countries," he told Conservative Home.

"But many of these changes have been blocked already or will be blocked by other government departments, while the government's stated policy of trying to control EU migration through benefits changes has been blown out of the water by its promise to introduce the biggest 'pull factor' of all: a new 'Living Wage' of £9 an hour by 2020."

The Office for National Statistics (ONS) said there were more than 206,000 student visas granted in the year to March 2016, a fall of 5% compared with the same period last year. The official statistics body also said visa applications from non-EU nationals to study in the UK fell by 6% to more than 222,000 in the year to March.