usSenior US senators are demanding that one of America’s biggest government pension funds reverse a decision that is set to channel billions of US dollars into funding Chinese companies that they say support Beijing’s military, espionage and domestic security efforts.

The demand shows how the US-China rivalry, which has thus far focused mainly on trade war tensions, is spreading further into the arena of financial markets.

Senators Marco Rubio, a Republican, and Jeanne Shaheen, a Democrat, told Michael Kennedy, chairman of the Federal Retirement Thrift Investment Board, in a letter that his fund is supporting Chinese state-owned companies with “the paychecks of members of the US Armed Services and other federal government employees”.

The letter — a copy of which was seen by the Financial Times — said an impending investment shift by the FRTIB would mean that about $50bn in US government pensions becomes exposed to the “severe and undisclosed” risks of being invested in selected Chinese companies.