Rep. Ed MarkeyEdward (Ed) John MarkeyRegulators seek to remove barriers to electric grid storage Markey, Paul want to know if new rules are helping opioid treatment Oil spill tax on oil companies reinstated as part of budget deal MORE (D-Mass.) released eight years of tax returns Friday that show he made about $150,000 per year and paid less than a 20 percent tax rate, according to The Boston Globe.

The newspaper notes that the Senate candidate significantly reduced his effective tax rate by taking a number of deductions — including for his mortgage, business expenses and his property tax.

Most of Markey's income came from his work in Congress, where he currently earns a salary of $174,000 per year. Markey, 66, has also begun to receive Social Security benefits.

The disclosure comes as Markey and his opponent in the special election, Republican Gabriel Gomez, have needled one another for disclosures.

Gomez released six year of returns Thursday that revealed he made $10.1 million over that entire period, mostly from private equity. Gomez had previously made his returns available during the primary campaign.

Democrats had pressed Gomez to release his tax returns going back to 2005, the year in which he claimed a controversial $300,000 tax deduction on his home, which has historical significance. The tax deductions had spurred attacks in the state.

Gomez’s camp had shot back that Markey had not released his returns despite receiving his congressional salary from taxpayers.

The campaign has entered a negative phase a month away from the June 25 election. Gomez has recently attacked Markey for airing ads that briefly reference the Newtown school shooting and one that shows a picture of Osama bin Laden alongside a picture of Gomez. Thursday night, Gomez called Markey “pond scum” when discussing the ads. He trails in the polls.