JEFFERSON CITY, Mo. — Missouri House Speaker Tim Jones accused Gov. Jay Nixon on Thursday of violating the will if Missouri voters by allowing same-sex married couples to file tax joint tax returns, as they now can at the federal level.

In a statement, Jones said Nixon’s executive order – which would recognize same-sex marriages for income tax purposes – “defies” a Missouri constitutional amendment passed in 2004 to ban same-sex marriages in Missouri.

“The Governor’s job is to defend our state’s constitution – including the constitutional amendment defining marriage as between one man and one woman, that was passed overwhelmingly in this state – not to surrender to the whims of the Obama administration,” he said. “This executive order is nothing but an attempt to violate the voters’ will, unlawfully ignoring a constitutional amendment to provide the Governor’s liberal allies a policy victory.”

Jones called on Nixon to provide a legal opinion from Attorney General Chris Koster, a Democrat likely to seek the party’s nomination for governor in 2016, to provide justification.

The state constitution bans same-sex marriage all together in Missouri, saying that only a marriage between a “man and a woman” should be recognized and valid in Missouri.

Nixon, in remarks to reporters earlier in the day, announced an executive order calling on the Missouri Department of Revenue to accept joint tax returns from all married couples, including same-sex couples married in other states. His order came after a similar announcement from the U.S. Department of Treasury giving same-sex couples the same tax status at the federal level.