A postponed meeting last month between Japanese and Chinese politicians was canceled because Beijing had demanded that Tokyo send more representatives than the number it sent to Taiwan in October, diplomatic sources said Saturday.

China requested that over 40 Japanese lawmakers take part in the meeting of their ruling parties in Gansu province, more than double the 19 who attended Taiwan’s National Day ceremony.

Beijing criticized the visit to Taiwan and said, “The number of Japanese lawmakers visiting China should be more than double that for Taiwan,” the sources said.

The request came as Taiwan President Tsai Ing-wen of the pro-independence Democratic Progressive Party appeared set to win again in the 2020 presidential election in January, according to local polls.

Taiwan and mainland China have been governed separately since they split amid a civil war in 1949. Beijing has made it increasingly clear it is willing to take all measures necessary to reunite what it considers a renegade province with the mainland.

Japan had only 33 members ready to participate in the meeting because the Diet was in the middle of an extraordinary session.

The group led by LDP Secretary-General Toshihiro Nikai was initially planning to travel to China in early November. The pro-China Nikai was seeking to meet Chinese President Xi Jinping during his stay.

The meeting was canceled even though Japan-China ties have been improving after being strained by issues of wartime history and territorial rows. The two neighbors are preparing for Xi to travel to Japan next spring as a state guest.

Earlier, the ruling parties said the visit to China was “postponed” without elaborating. It has yet to be rescheduled.

Since its launch in 2006, the meeting was held until 2009 before relations deteriorated over territorial disputes. It restarted in 2015.

An LDP member said, “Democracy movements in Taiwan and Hong Kong have affected diplomatic exchanges between Japanese and Chinese lawmakers”.

Beijing is struggling to contain the months-long demonstrations and riots in Hong Kong, while closely watching the election in Taiwan.