Updated 3:30 p.m.

Gov. Bob McDonnell (R) is urging Senate Democrats to do their part to write a state budget.

In a letter to Democratic leaders, Sens. Richard Saslaw (Fairfax) and Don McEachin (Henrico), McDonnell asked senators to provide him and Senate Finance Chairman Walter Stosch (R) with budget proposals, which they have not done so far.

Virginia Gov. Bob McDonnell presents his budget before a joint session of the House and Senate money committees at the Capitol in Richmond, Va., Monday, Dec. 19, 2011. (Steve Helber/AP)

Senate Democrats will play a key role in approving a budget this year, even though Republicans control the equally divided chamber. That’s because Lt. Gov. Bill Bolling, who presides over the Senate, has said he can’t vote on the budget.

“I trust that certain comments made by some members that your caucus will not approve any budget for partisan reasons is not reflective of the statemanship normally seen in your caucus,’’ McDonnell wrote in a letter dated Tuesday, but released Thursday. “We must work together now to get our job done on time.”

Senate Democrats responded in a letter to McDonnell, saying their concerns are “not partisan, but substantive.”

“Immediately after the election, when we could have and should have been coming together, you and the rest of your party engaged in harsh partisan rhetoric,’’ Saslaw and McEachin wrote. “Therefore, I find your concerns about partisanship to be rather ironic. Further, your release of your letter without waiting even twenty-four hours for a response smacks of gamesmanship and not of an effort to resolve our differences. In light of the release of your letter to the press, we are releasing our letter as well.”

McDonnell released his two-year budget proposal in December. The House and Senate will unveil their alternatives to that budget Sunday. The two chambers must reconcile differences in their budgets before the General Assembly adjourns March 10.