A pension fund for federal workers on Wednesday said it will begin tracking a benchmark that includes China-listed companies, despite strong opposition from a bipartisan group of Senators.

The decision by the Federal Retirement Thrift Investment Board (FRTIB), an independent government agency that oversees the Thrift Savings Plan (TSP) retirement fund, comes amid heightened trade tensions with China and efforts to limit the flow of U.S. capital to Chinese companies due to security concerns.

It also bucks months of political pressure from a group of U.S. senators led by Republican Marco Rubio and Jeanne Shaheen, a Democrat, who this month introduced legislation dubbed the TSP Act to block TSP from making the benchmark switch.

The House of Representatives has introduced a similar bill. In a statement, Rubio described the decision as “unconscionable” and “foolish,” adding: “The Board’s refusal to act in the best interests of the United States will not go without consequence.

I urge my colleagues to quickly pass our bipartisan and bicameral TSP Act.” The FRTIB said in a letter to the senators that its decision to use the MSCI All Country World ex-U.S. Investable Market Index as the benchmark for its international stock fund came after recommendations from a consulting firm.

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