Photo taken on Jan. 17, 2017 shows the Lancaster House in London, Britain, where British Prime Minister Theresa May is to give details about her plans for Britain's exit from the European Union . (Xinhua/Han Yan)

LONDON, Jan. 17 (Xinhua) -- British Prime Minister Theresa May said for the first time Tuesday that Britain will leave the European Single Market.

In her first major speech outlining her Brexit strategy, the tough talking prime minister spelled out her 12-point roadmap for Britain's eventual divorce from its 27 EU neighbors.

May said she wants a trade deal with the EU to operate within Europe, saying "what I am proposing can't mean membership of the European Single Market."

Instead she wants a comprehensive trade agreement that gives free access to Britain to European markets, removing as many trade barriers as possible.

Her message will come as a blow to remain supporters who see free access to the EU Single Market and access to a huge trading bloc of almost 500 million people as crucial for the British economy.

Brussels has insisted free access is not possible without free movement of people, something May rejected in her speech.