As of 12.30pm last Wednesday, the UK formally expressed its intention to leave the EU by triggering Article 50. A six-page letter was delivered to the president of the European Council, Donald Tusk, by Tim Barrow, Britain's envoy to the EU, officially starting the process of withdrawal and of negotiations on our future relationship.

The Government has published the Great Repeal Bill, the first step in bringing current EU laws under the UK's control, which will allow Parliament to reconsider and amend them.

Leaving the EU represents the most significant change in direction for the UK since the 1960s, when the consensus was emerging that the UK should join.

The principle of reclaiming our national sovereignty is simple, but there is now the momentous task of making hundreds of individual decisions as to where we as a nation go from here.

The Government must handle the exit negotiations and formulate a new relationship, while Parliament must also pass new laws for policies controlled by the EU, as well as amending existing UK policies on matters like immigration, fisheries and agriculture. At the same time, the new Trade department must set up the new arrangements for the UK to trade with the rest of the world from outside the EU bloc.

The EU is an important trading partner, but its significance to the UK economy has been declining for a decade or more. In 2005, 55% of all goods and services exports went to the EU, and 58% of all imports came from the EU. In 2015, less than half our goods and services exports went to the EU (44%) and we imported only 53% of all imports from the EU.

And the relative importance of non-EU trade has increased, especially in the export of services. This is important because the EU's record of completing trade deals with other countries is poor. For example, the EU has not concluded trade deals as yet with either the USA or China – the UK's two largest non-EU export and import markets.

We are not leaving Europe, but by leaving the EU we can join the rest of the world and forge ties with other nations, including countries such as China, India, Australia and New Zealand, that do not currently have preferential trade agreements with the EU. It will also enable us to free UK business from some of the sillier EU regulations.

This does not mean we do not wish to continue to enjoy a good relationship with our closest friend and neighbour. It simply means that membership of the EU is not best for Britain.

The UK is about to embark on the most important negotiation for the future of our country in a generation. I am more confident than ever that the Government will make it successful – not just for business but for people, incomes and jobs, and for the self-confidence of the country as a whole.