TOKYO, July 8 : Japan's ruling party plans to propose stronger enforcement against suspected violations of shareholder disclosure rules by activist investors, including by providing more resources to the securities watchdog, a senior lawmaker told Reuters.The proposals come as Japan has become one of the world's busiest markets for activist investing outside of the U.S., attracting hedge funds that have pushed companies to raise returns, unwind cross-shareholdings and improve governance."The presence of activists has created healthy tension for management and helped drive positive change," said Fumiaki Kobayashi, who heads a group of Liberal Democratic Party lawmakers examining corporate governance."But there are cases where short-term demands by some activist shareholders may discourage g