Theresa May was last night told to let more Indians into Britain – or miss out on trade deals with the Delhi government

Theresa May was last night told to let more Indians into Britain – or miss out on trade deals with the Delhi government.

In provocative remarks likely to deepen the row over immigration controls, India's High Commissioner warned the Prime Minister: 'Post-Brexit, you need Indians.'

The intervention by Dinesh Patnaik, India's most senior diplomat in London, comes as Mrs May flies out to his country today to try to drum up new trade deals to cushion the impact of leaving the EU.

Top of the Indian government's list of demands will be the reversal of tough immigration measures Mrs May imposed on their citizens when she was Home Secretary.

But she will also face calls to take a harder line on neighbouring Pakistan's alleged link to global terror – and even to allow more Indian mangos into Britain.

Mr Patnaik said his government objected to the restrictions faced by tourists and Indian students hoping to study in Britain, adding: 'Students, tourists and short-term visitors are not migrants under any definition.

'Post-Brexit, you need Indians. Our tourists… don't come to Britain due to difficult visa conditions.'

The number of Indian students at UK universities has fallen from 39,090 in 2011 to under 20,000 since Mrs May, then in the Home Office, abolished visas that allowed all non-EU students to seek jobs here for up to two years after the end of their studies.

During her three-day visit, the Prime Minister will also be lobbied to allow tariff-free and regulation-free access to our market for produce, such as mangos. Last year, the UK was forced to comply with a recently lifted Brussels ban on the fruit over fears they might be infested with flies.

The row over Indian visas mirrors the battle within Government over the level of migration controls Britain should introduce after leaving the EU.

During her three-day visit to India, the PM will be lobbied to allow tariff-free and regulation-free access to our market for produce, such as mangos. Last year, the UK was forced to comply with a recently lifted Brussels ban on the fruit over fears they might be infested with flies. File picture

Brexit 'doves' such as Philip Hammond have been arguing for fewer restrictions on the free movement of labour from EU countries in return for access to the Single Market.

Mrs May has chosen India for her first trade mission as Prime Minister because officials believe the historic business links between the two will help British businesses to ride out the turbulence caused by leaving the EU.

India is the third-largest investor in the UK, and British Government officials argue leaving the EU will allow us to 'unlock the potential' and forge a 'more ambitious trading relationship'. Defence deals are top of the agenda.

Mrs May, who will take 33 business representatives with her, last night said the trip demonstrated she was forging ahead with delivering Brexit – despite the calls by Remain-supporting MPs and peers for Parliament to debate her negotiating terms.

'While others seek to tie our negotiating hands, the Government will get on with the job of delivering the decision of the British people,' she said.

The Prime Minister added: 'The UK and India are natural partners – the world's oldest democracy and the world's largest democracy – and together I believe we can achieve great things.'