London has the highest concentration of top universities in any city in the world, however the number of Indian students in London has more than halved in the past five years.

Johnson is set to urge UK ministers to introduce a Commonwealth work visa as well as a work visa available only to STEM graduates soon.

The Commonwealth work visa, which would first be rolled out to Indian students, would enable them to stay and work in the UK for two years after graduating.

Johnson proposes that if successful, it could be extended to students from other Commonwealth countries.

“We should make sure we are doing all we can to encourage young people to study here and experience everything London has to offer”

“Current restrictions on overseas students are putting off the brightest Indian minds from coming to study in the capital,” he said.

“And it is crazy that we should be losing India’s top talent and global leaders of the future to countries like Australia and the United States.”

Meanwhile, a proposed work visa for graduates of STEM degrees would enable them to stay and work for two years post-graduation.

A statement from the mayor’s office said that while this would not be restricted to any one nation, “this would be attractive to Indian students for whom STEM degrees are popular”.

“It would also help to meet a critical skills shortage in the UK in areas such as life sciences, engineering and technology,” it added.

The Indian student market in London has been falling by 11% annually according figures released by London and Partners.

In 2009/10 there were 9,925 Indian students in the capital but the number dropped to 4,790 in 2013/14.

“It is widely speculated … that the decline can be attributed to a change in post-study visa requirements,” says its report on the economic impact of London’s international students.

A recent study by Hobsons found that “post-study work options”, and “job prospects or migration to the destination country” were the main reasons why international students are not choosing to study in the UK in general.

The London and Partners study also found that international students at London universities directly contributed £3bn to the UK economy in 2013/14, however stakeholders fear the government will impose further restrictions on international students as net migration figures reached an all-time high in August.

“International students bring a wealth of benefits to the city,” said Gordon Innes, CEO of London and Partners.

“At a time when we are facing increasing competition from many other countries, we should make sure we are doing all we can to encourage young people to study here and experience everything London has to offer.”