TOKYO, June 20 (Reuters) - Japan's Nikkei soared to a one-week high on Monday, posting the biggest daily gain in two months as Brexit worries receded somewhat after weekend polls showed the campaign to keep Britain in the European Union regaining momentum.
The safe-haven yen weakened on the uptick in risk appetite and helped lift the Nikkei share average 2.3 percent to 15,965.30, the highest closing level since June 13. The index posted the biggest daily percentage gain since April 21.
The broader Topix gained 2.3 percent to 1,279.19, with 90 percent of issues listed on the main board ending in positive territory. The JPX-Nikkei Index 400 rose 2.3 percent to 11,526.29. (Reporting by Ayai Tomisawa; Editing by Shri Navaratnam)