The 97th Congress reconvenes today for a high-stakes final fling before the November elections, with the scheduled curtain raiser a House vote tomorrow on President Reagan's veto of a $14.1 billion supplemental appropriations bill for the rest of this fiscal year.

There is likely to be a full month of such money crunches aggravated by political posturing and funding deadlines that could keep the government in turmoil until after the new fiscal year starts Oct. 1.

Congress may also take up where it left off on assorted other issues ranging from abortion to wilderness protection, from prayer in schools to pesticides on farms.

But time is so short and the agenda is so overwhelmed by politics that it is doubtful whether Congress will do much more than absolutely necessary to keep the government operating next fiscal year. It is even doubtful that it will be able to pass more than one or two of next fiscal year's regular 13 appropriations bills by the theoretical deadline of Sept. 30, meaning the government will have to run once again on a so-called "continuing resolution."

Such highly publicized and heavily lobbied issues as a constitutional amendment to balance the budget could get lost in the shuffle, along with major environmental, crime and immigration legislation.

If Congress can get the government safely launched into fiscal 1983 on or about Oct. 1, it plans to leave town again shortly thereafter to let members campaign for reelection on Nov. 2. Neither House nor Senate would then return until the 98th Congress is seated in January unless they are called back after the elections for a lame-duck session to deal with money problems and Social Security, which is considered possible.

About all that is certain is that Reagan will dominate the session's windup, as he did its start, with his demand for more defense spending and less for domestic programs.

With the upper hand that the veto power gives him, he can be expected to try to portray Congress as profligate on spending and needing discipline. But win, lose or draw, it is the Reagan agenda that Congress will be operating from when the voters get their last preelection look at their lawmakers in action.

This is a rough outline of what they will see:

* First, Congress must dispose of the supplemental appropriations bill, either by overriding Reagan's veto, which requires a two-thirds vote of both houses and is thereforce considered unlikely, or by passing a compromise that the president will sign. It has only until Sept. 15 to do so because that is when the Pentagon as well as many domestic agencies are expected to run out of money to meet their payrolls.

* In the meantime, Congress must make as much progress as it can in passing appropriations bills for fiscal 1983 and wrap the rest into a continuing resolution to fund the government after this year's appropriations expire on Sept. 30. At least some action on individual money bills is important because they are likely to provide the spending levels for the continuing resolution, which could last for months. As of now, Congress has passed no appropriations bills, with only four reported so far by the House Appropriations Committee, where they must originate.

* Finally, Congress must also act by Oct. 1 to raise the federal debt limit because existing borrowing authority runs out then. Failure to meet the deadline for this legislation, which calls for a new debt ceiling of $1.29 trillion to last through the next 12 months, would leave the government without borrowing authority and plunge it into another financing crisis.

Rarely if ever have Congress and a president faced so many critical financing deadlines all at once. Failure to meet any one of them could mean a disruption in daily activities of the government. A little less than a year ago virtually the entire government, right up to the visitors' deck atop the Washington Monument, shut down for a day when Reagan and Congress could not agree on spending levels for a continuing resolution for the current fiscal year.

There is one deadline -- Sept. 15 for passage of a final budget resolution--that Congress can ignore.

In passing its first budget resolution last spring, it decided that the spending targets in that preliminary measure would become binding if the second resolution called for by the budget process was not passed by the end of September.

No further budget action is planned, meaning a deficit of $155 billion for fiscal 1983, under the latest projection by the Congressional Budget Office.

This week, as the House wrestles with the appropriations veto, the Senate will resume its consideration of abortion controls.

Today it is scheduled to take up a constitutional amendment sponsored by Sen. Orrin G. Hatch (R-Utah) to give Congress and the states joint authority to restrict abortions. Tomorrow it is scheduled to vote on a motion to shut off debate on a separate legislative proposal to restrict abortions that Sen. Jesse Helms (R-N.C.) is seeking to tack onto the debt ceiling bill. Reagan has come out in favor of this. Also pending as a rider to the debt bill is a Helms proposal to keep federal courts from barring prayer in public schools.

Senate leaders are hoping to dispose of the abortion-prayer controversy in time to get the debt measure out of the way before the late-September crunch over the continuing resolutions rolls around. But other amendments are possible and quick passage is not assured.

Several important measures have passed one house but not the other and could fall by the wayside in the final rush toward adjournment.

Given a better chance than most is a Senate-approved major revision of immigration laws that includes civil and criminal penalties for employers who knowingly hire illegal immigrants and amnesty for millions of illegal immigrants who are already in this country.

Considered less likely to win final congressional approval is the Senate-passed constitutional amendment to require balanced budgets in peacetime unless three-fifths of both houses vote to allow deficits. The House Judiciary Committee is considering proposals to water down the amendment, and an effort to discharge the committee from consideration of the amendment has so far fallen short of the 218 signatures necessary.

Final action is also possible on Senate-passed legislation to control disposal of nuclear waste, but approval of amendments to the Clean Air Act, mired in controversy in the House, appears less likely.

Clean Water Act amendments have not even gone to the floor of either house. Revision of the Endangered Species Act has been approved by both houses but there has been no conference action. Action is possible but not certain on legislation governing use of pesticides and regulating farmers' access to cheap water from federal reclamation projects.

A foreign aid authorizing bill is also pending, but one of its key elements, the administration's Caribbean Basin Initiative, could be dealt with in the war between Reagan and Congress over the supplemental appropriations bill. Even Republicans warned the administration it could lose its Caribbean aid money if Reagan vetoed the appropriations bill.

Another administration bill to authorize a new government radio station to broadcast to Cuba (Radio Marti) has passed the House but is bottled up in a Senate committee.

A bill to provide $1 billion in jobs money for areas with high unemployment ranks high with House Democrats, but is not expected to get through the Republican Senate.