The Middle Eastern state of Qatar said that it was optimistic about the future of the British economy.

It made it clear that the UK leaving the European Union had little bearing on its decision.

Qatar has already invested £40bn in the UK - it owns Harrods and a 95% stake in the Shard in London.

It also has a stake in Canary Wharf in the capital's Docklands, as well as an interest in the Milford Haven liquefied natural gas terminal in South Wales.

It also bought the Olympic Village following the London 2012 Olympics.

"Currently the UK is our first investment destination and it is the largest investment destination for Qatari investors, both public and private," Ali Shareef al Emadi, the country's finance minister, told the BBC.

"We have more than £35bn to £40bn of investments already in the UK.

"We're announcing an additional £5bn of investment in the next three to five years.

"Mainly this investment will focus on infrastructure sectors, technology, energy and real estate."

Mr Al Emadi will join International Trade Secretary Liam Fox in Birmingham on Tuesday where UK firms will showcase projects, including in sport, cyber-security and healthcare.

The government relies on foreign investment to support infrastructure projects such as the new high speed rail link between London, Birmingham and Manchester - HS2.

Although no final decisions have been taken on the Qatari investments, Mr Al Emadi did not rule out putting money into HS2.

"We will look at those deals; we will look at electricity, roads, bridges, railways," he said.

The announcement of the Qatari investment is likely to be welcomed by Number 10.

It comes two days before the triggering of Article 50, the official process for leaving the European Union.

Theresa May has made it clear she believes the British economy remains a positive place to invest and the Qatari announcement follows UK-focused investment decisions by Sir James Dyson, Google and Nissan.

'Confident'

The decline in the value of sterling has made UK assets more attractive to overseas investors - though many economists argue that leaving the EU will damage trade with Britain's largest market and therefore damage growth.

"We always like the UK market, it has always been a good market," Mr Al Emadi told me.

"The way we look at our investment in any market, and especially in the UK, it is a very long term investment, so we don't look at any cycles up or down

"So if you are talking about Brexit, I can go back to the financial crisis and tell you the same stories.

"We will do what we think is good for us, it is commercially viable, it has a good vision and a good impact."

I asked him whether the UK economy outside the EU was likely to be stronger or weaker.

"It is a lot to do with the policy the UK will take, but I think, knowing the UK market, I am very confident they will have a good future," Mr Al Emadi answered, saying that it was important that Britain was welcoming to high skilled foreign workers and students from Qatar and elsewhere.

Qatar has faced controversy over a fundraising for Barclays Bank at the time of the financial crisis and - more recently - allegations that poor labour conditions have marred the preparations for the 2022 World Cup which is being held in the country.

Mr Al Emadi said that Qatar had supported job creation in the UK.

"If you look at what we have done here, it has always been a win-win situation, whatever investment we do in the UK," he said.

"When you talk about labour in Qatar, I think a lot of these things have been taken out of proportion and [are] inaccurate news."