Sir Keir Starmer has said the UK will not relax visa rules for India, speaking before he arrived in the country to tout the benefits of a recent trade agreement.

The prime minister is leading a delegation of more than 100 entrepreneurs, cultural leaders and university vice chancellors, as he attempts to boost UK investment and improve sluggish economic growth.

Sir Keir said there were "massive opportunities" to improve trade and cultural ties with India.

But he said there were no plans to open up more visa routes to Indian workers or students.

"The issue is not about visas," Sir Keir said. "It's about business-to-business engagement and investment and jobs and prosperity coming into the United Kingdom."

The UK's trade deal with India was signed in July after years of negotiation.

It will mean UK cars and whisky will be cheaper to export to India, and Indian textiles and jewellery cheaper to export to the UK as part of the multi-billion pound trade boost.

The deal included a three-year exemption on social security paid by Indian employees working in the UK on short-term visas.

But ministers insisted there were no wider changes in immigration policy.

The Labour government is trying to cut levels of immigration into the UK and announced a tough policy on settlement status at the party's conference last week.

Speaking to reporters on the plane on the way to Mumbai, Sir Keir said visas "played no part" in the trade deal with India and that situation had not changed.

Asked whether the UK might consider trying to attract tech entrepreneurs in the wake of US President Donald Trump's changes to the H-1B visa in the US, Sir Keir said the UK wanted to attract "top talent" from across the globe to help grow the UK economy, but repeatedly said there were no plans for new visa routes to India.

Among the businesses travelling with the PM was British Airways, which announced plans to introduce a third daily flight between Delhi and Heathrow next year.

Manchester Airport also revealed a new direct route to Delhi.

During the two-day trip, the prime minister is expected to meet Prime Minister Narendra Modi who ahead of Sir Keir's visit had conveyed his "warm birthday greetings" to Russian President Vladimir Putin on social media.

Sir Keir said he would not be following suit, telling reporters: "Just for the record, I haven't sent birthday congratulations to Putin, nor am I going to do so. I don't suppose that comes as a surprise."

Asked whether he would criticise Modi over India's purchase of Russian oil, Sir Keir said the UK's focus was on Russia's shadow fleet of oil tankers.

The prime minister said the UK had been one of "the lead countries in relation to the 'shadow fleet'" - the name given to unregulated tankers ferrying oil from Russia.