Gov. Charlie Baker will file legislation Friday to freeze the tax rates that businesses pay into the state's unemployment system, aiming to stave off a massive increase set to hit over the next few years triggered by soaring demand for joblessness aid.

Baker said at a COVID-19 press conference that he would propose a bill later in the day keeping unemployment insurance trust fund contribution rates level and enabling Massachusetts to issue special bonds to help repay federal loans that have kept that fund solvent during the pandemic.

Under the status quo, the unemployment insurance trust fund faces a massive deficit due to an unprecedented volume of claims filed and paid amid the COVID-19 pandemic and recession.

The Baker administration's Executive Office of Labor and Workforce Development projected earlier this year that the average per-employee contribution businesses are required to pay would rise from $539 in 2020 to $858 in 2021 and then $913 in 2022, followed by subsequent smaller hikes.

Freezing the rates at their current schedule would provide "immediate and important relief for all businesses across the commonwealth," Baker said. Issuing bonds to pay back the federal government will help ensure Massachusetts residents can continue to access benefits, he added.

Massachusetts has received more than $2.2 billion in federal loans to help keep the unemployment insurance trust fund solvent enough to pay out claims, according to federal data.