Andrew Mitchell is a former International Development Secretary, and is MP for Sutton Coldfield.

Brexit has changed everything. It will lead to a fundamental adjustment in all our external relations. Policies on aid and trade that have been inextricably tied up with the EU over the last four decades will once again need to be conducted on a bilateral basis.

This is an immense undertaking. But it is also an extraordinary opportunity. A post Brexit foreign policy will see us pursuing our national interests with renewed vigour and the direct means to do so.

A good place to start would be to focus on countries with which we share history and mutual understanding. A second priority should be to identify the countries with the assets and political will to drive prosperity and development over the next thirty or forty years. The final consideration should be strategic interest.

There are many countries that meet one or more of these criteria. One of the few that meets all three is Nigeria, a country with the potential to emerge as a genuine continental leader and one of the world’s most dynamic economies over the next few decades.

This may cause some surprise. Nigeria is rich in human and material resources, yet it has been held back for decades by the interrelated problems of chronic corruption, oil sector dependency and low levels of human development.

Corrupt earnings totalling $178bn (equivalent to 5.7 per cent of GDP) are estimated to have flowed out of Nigeria between 2004 and 2013. Despite an abundance of fertile land, the agricultural sector has been allowed to stagnate and Nigeria currently has to spend around $6.5bn annually on importing food.

Another huge challenge has come in the form of the terrorist insurgency waged by Boko Haram, the ISIS affiliate that has brought death and destruction to large parts of northern Nigeria. This has exacerbated many of the country’s existing problems of poverty, exclusion and under-development.

The reason for being optimistic about Nigeria’s prospects is that it now has a President that appears determined to get a grip on all these problems and put the country on a new and better path for its future.

President Buhari’s administration has begun to diversify and rebalance the economy by reducing dependency on extractive industries, focusing on non-oil exports, investing in infrastructure and boosting the agricultural sector. Concerted action is being taken to root out corruption by stepping up the investigation and prosecution of corrupt officials, identifying and returning stolen public funds, and making public finances more transparent and accountable.

From my experience at DfID I know these are areas where the UK can play a strong supportive role, as we did when we secured the prosecution of former Nigerian state governor, James Ibori, on charges of corruption in 2012.

Progress is also being made in the fight against terrorism. Over the last year, Nigerian security forces have managed to gain the upper hand, pushing Boko Haram out of more and more areas. The United States has resumed security co-operation that was cut off because of well-grounded concerns about corruption and human rights under the old government.

West Africa is now one of the key battlegrounds in the global war against violent Islamism, and Nigeria holds the key to defeating an enemy that has also created havoc in the neighbouring countries of Chad, Niger and Cameroon. This is an area where the UK can and should make a greater contribution in terms of expertise and material support.

If Nigeria can restore internal security and continue to improve the quality of its governance, its prospects for the future are extremely bright. Much of this latent potential comes from the extraordinary energy of its people.

Already Africa’s most populous country, estimated at 180 million, and with two-thirds under the age of twenty-five, Nigeria has a young, dynamic and creative population. Nigeria’s remarkable demographic profile and underlying economic potential constitutes a great opportunity for a post-Brexit UK.

Recognised as Africa’s largest economy, Nigeria has been identified as one of four countries belonging to the MINT group of rapidly emerging economies alongside Mexico, Indonesia and Turkey. On current trends, the case for its inclusion among the G20 is likely to become irresistible within a few years.

The UK has a golden opportunity to develop a strategic partnership of lasting mutual benefit with Nigeria. We share strong historic ties, membership of the Commonwealth, a common language and much more besides. There are more than 200,000 Nigerians now living in the UK. Nigerian children are among the highest performing in our schools.

This generation has the capacity to be a transmission belt carrying ideas, energy and prosperity between both countries for many decades ahead. It only remains for our leaders to see the opportunities and to seize them.