THE MAIN issue at the highest levels of government this week has not been the deficit or the savings and loan bailout or the defense or campaign finance or farm or housing or civil rights bills. It has been the images of the two parties as Congress prepares to leave town for the month of August with much of the government's business undone and an election approaching. To what extent will each party have to play defense until the government starts up again; to what extent can each position itself to take the offensive?

It has been clear for some time that the budget negotiators for the president and Congress weren't going to reach an agreement before the recess. With nothing much likely to happen for the month, the question became the posture in which matters would be left. The Republicans, or some of them, feel burned because the last proposal leaked (though not formally made) was theirs and the Democrats cunningly haven't made one. The Republicans thus go home having somehow to defend a proposed tax increase on beer and/or a cap on the federal tax deduction for state and local income taxes, both parts of the president's proposal. The Democrats, having been silent, have no such burden. The Republicans are trying to shift the issue by accusing the Democrats of having jeopardized the talks and the economy by sitting on their hands. But having traded accusations, they'll all return to the bargaining table in September; they have no choice.

In Congress, meanwhile, the Democratic leadership, sometimes with Republican help and sometimes over Republican objections, is busily moving major legislation as if the practice were going out of style. Both armed services committees have reported bills making sharp cuts in the administration's defense program. The Senate Democrats are forcing through a campaign finance bill; the House passed a major housing and a five-year farm bill in the same day yesterday. As of last night, the House leadership was still contemplating bringing up -- and passing -- the civil rights bill today, campaign finance tomorrow and maybe an airport and airways bill somewhere between. Not a bad defense (with most of the appropriations bills also passed) against a charge that the House was neglecting its responsibilities.

There is, of course, another reason for all this activity. Congress always waits until the last minute to do its most important work and in election years makes matters worse by trying to adjourn early to campaign. It's not just that the members want to look good as they leave town for a month; in part because they're leaving town, they're running out of time.