President Joe Biden has vetoed bipartisan legislation that would have added dozens of new federal judge positions in the coming years.

The president had threatened to veto the bill because he didn’t want to give the president-elect new appointment opportunities, according to one of the outgoing president’s closest allies.

“The House of Representatives’ hurried action fails to resolve key questions in the legislation, especially regarding how the new judgeships are allocated,” Biden wrote in a letter to Congress.

Democrats had roundly faulted House Republicans for waiting until after the results of the November elections — won by President-elect Donald Trump — to pass the legislation. As authored, the bill would award some 66 new federal judicial slots over the next three presidential terms.

The bill passed the Senate unanimously in August. It cleared the House on a largely party-line vote earlier in December.

Democrats have been seeking ways to insulate the federal judiciary from Trump’s desires to move it further to the right, including by denying the incoming president further vacancies to fill in the bench.

The bill’s lead Senate sponsor, Sen. Todd Young (R-Ind.), was sharply critical of the veto.

“Issuing this veto is partisan politics at its worst,” Young said in a statement.