In the first visit by a Prime Minister to the sub-Sahara in five years, Mrs May will take two dozen business chiefs in a bid to whip up a slew of high investment deals.

And as the first British PM to visit Kenya in 30 years, she will address British troops training anti-jihadi forces in Nairobi.

Mrs May said: “As we prepare to leave the European Union, now is the time for the UK to deepen and strengthen its global partnerships.

"This week I am looking forward to discussing how we can do that alongside Africa to help deliver important investment and jobs as well as continue to work together to maintain stability and security.”

She was given a pre-visit boost as African politicians backed plans to use Brexit to forge closer links with the Commonwealth.

Nigerian Presidential hopeful Atiku Abubakar said: “It is time to release the African lion economies such as Nigeria, South Africa and Kenya. We can be the catalyst for a worldwide Commonwealth trade deal with none of disadvantages of the EU's attempt to run Britain from Brussels.”

The country’s former Vice President added: “My sincere belief is that Brexit can be a great force for good. It could blow down barriers which have prevented Nigeria and other countries from grasping their potential.”

He went on: “time and again we are hit by EU tariffs on products such as sugar cane and rice. This is aimed at protecting European producers, often for products which are not farmed in Britain.”

Downing Street hope the visit will help the UK forge better trade links with the continent that is home to 16 per cent of the world’s population but just three per cent of international trade.

Mrs May will use a speech in Cape Town on Tuesday to make her pitch, saying: “Africa stands right on the cusp of playing a transformative role in the global economy, and as longstanding partners this trip is a unique opportunity at a unique time for the UK to set out our ambition to work even closer together.

“A more prosperous, growing and trading Africa is in all of our interests and its incredible potential will only be realised through a concerted partnership between governments, global institutions and business.”

Representatives from export giants JCB, Scotch whisky producers and infrastructure chiefs will travel with the PM.

As will City bosses and the Lord Mayor of London.