This post has been updated.

Grover Norquist, founder of Americans for Tax Reform (Photo by Bill O'Leary/The Washington Post)

“Plain and simple, both bills are job-killing tax increases,’’ Norquist wrote. “Increasing the gas tax by indexing it to inflation is bad business practice for Virginia. The transportation woes Virginia faces are not beacuse of the gas tax. Richmond has spent too much money; in other words, it’s a spending problems not a revenue problem.”

Update, 3:45 p.m.

Senate Republicans responded to the letter late Thursday afternoon. “As transportation proposals of the House and Senate will be negotiated in the coming weeks, our members are always appreciative of constructive input on the various proposals,’’ said Jeff Ryer, a spokesman for the Senate Republican caucus.

The Senate voted 26-14 to for a proposal that would raise the gas tax along with the rate of inflation. Seven Republicans voted for it, including Senate Majority Leader Thomas Norment (James City) and Sen. Walter Stosch (Henrico), chairman of the Senate Finance Committee.

The change in Virginia’s 17.5 cent gas tax, which hasn’t increased since 1986, would bring in an additional $123.6 million each year by 2018.