A political organization funded by a top hotel-trades union has helped develop a multifaceted lobbying effort to persuade New York City politicians to curtail Airbnb, according to emails and records reviewed by The Wall Street Journal.

The group known as Share Better has written talking points and op-eds for City Council members, arranged meetings and suggested new rules for home-share services. The president of the 32,000-member New York Hotel Trades Council, which has funded Share Better, has met with Mayor Bill de Blasio...