Tokyo shares ended the morning session lower on Tuesday, with the Nikkei index briefly plunged to its lowest intraday level in five weeks ahead of British Prime Minister Theresa May's speech on Britain's plans to exit the European Union due later in the day. 
The 225-issue Nikkei Stock Average declined 113.67 points, or 0.60%, from Monday to 18,981.57. 
The broader Topix index of all First Section issues on the Tokyo Stock Exchange fell 10.82 points, or 0.71%, to 1,519.82. 
Decliners were led by food, real estate and bank issues.