After a final burst of lobbying that included wake-up calls from Vice President Mondale, the house Government Operations Committee yesterday approved creation of a federal consumer protection agency. The photo-finish vote was 22 to 21.

Hotly opposed by business interests who contend that it will only lead to "a meddlesome new bureaucracy," the measure still faces a stern test on the House floor although some proponents contend that yesterday's was the crucial vote.

The bill would create a $15-million-a-year agency with authority to intervene on behalf of consumers before most government agencies and to challenge adverse decisions and programs in the courts.

The cajolery and buttoholing, which began earnest last month after President Carter endorsed the legislation in a special message, continued right up to the showdown.

Moments before the meeting began yesterday morning, Rep. Robert Drinan (D-Mass.), a Jesuit priest and strong supporter of the measure, walked up to one of the committee Democrats whose vote was a doubt, Rep. Michael T. Blouin of Iowa.

"I understand you're in need of spiritual help," Drinan told him with a solicitous smile and a voice loud enough to be heard at the press table nearby.

"I've already had it: Fritz (Mondale) called me at 8 o'clock this morning," Blouin replied, indicating that he was still half asleep when the Vice President called.

"He'll kick you out of the party," Drinan warned in joking tones. "I'll kick you out of the church."

Elsewhere in the high-ceilinged hearing room, White House consumer adviser Esther Peterson had just been told by business lobbyists that they had lined up 22 to 24 votes - enough to kill the bill. Consumer advocate Ralph Nader walked in, looking concerned. Rep. Richardson Preyer (D-N.C.) was telling reporters how he'd been getting one call after another from businessman friends back home in his district where textiles are the big industry and organized labor is weak.

Preyer said he planned to hold firm and vote for the bill, but others, like Rep. Floyd M. Fithian (D-Ind.), were resisting entreaties such as a weekend letter from Carter and another follow-up call from Mondale.

The votes of still other members, such as Blouin, remained uncertain until the end. He wanted to tack several amendments onto the bill in exchange for his support. The first, exempting family farms and small businesses with assets up to $5 million (instead of $1 million) from inquiries the new agency could make on behalf of consumers, was readily accepted by the chief House sponsor of the bill, Rep. Bejamin S. Rosenthal (D-N.Y.), without a vote.

Blouin's next proposal, however, produced a striking display of the uneasy alliances that made the committee's final vote so difficult to predict. In addition to the string of exemptions the bill already accords to "raw agricultural commodities," Blouin wanted to exempt the Department of Agriculture's export-import policies from judicial challenge by the new agency.

Opponents of the bill, such as Rep. Elliott H. Levitas (D-Ga.), said they were "aghast" at the suggestion.They said it would keep the agency from going to court to block such deals as the controversial Russian wheat sales of 1972. Blouin insisted that farmers ought not to be held up by protracted court fights from deciding what to plant.

In the roll call that followed, Blouin was supported by big city Democrates such as Drinan, Rosenthal and Rep. Michael Harrington (Mass.), ostensibly on behalf of rural America. But farm state Republicans, such as Reps. Robert Kasten of Wisconsin and Charles Thone of Nebraska, voted no, refusing to exempt agricultural export-import decisions from judicial review. Blouin's proposal was rejected, 23 to 20.

"It's an unholy alliance," Kasten explained during a recess, saying the backers of the bill were trying to buy Blouin's vote. "He said he'd vote for the bill on final passage if this amendment were adopted . . . Charlie Thone and I would both have preferred to vote 'for the farmer'" but, Kasten said, they wanted even more to block the bill.

Minutes later, Nader walked up to Blouin and asked how he planned to vote on final passage. The Iowa Democrat insisted that he still didn't know, then aded that "it'll help" if his third amendment, a "sunset" provision calling fro abolition of the agency by 1985 unless it can justify continued existence, could be adopted. It was, with the deadline moved up to 1982 at the urging of Rep. Paul N. McCloskey Jr. (R-Calif.).

With two amendments out of three adopted, Blouin then voted for the bill on the final 22 to 21 roll call.

By the accounts, however, the yes vote was a shade more secure than that Rep. John W. Jenrette (D-S.C.) had promised the White Hosue to vote for the bill if his support were essential to getting it out of the committee.

It wasn't necessary, so Jenrette, the last to vote yes or no, voted no.

The same House committee, with a slightly different membership, had supported a similar bill two year ago by a top-heavy 30 to 10. Both House and Senate subsequently approved their own versions, but never sent the legislation to the White House. President Ford had vowed to veto it, and the House vote was only 208 to 199, not enough to override.

Rosenthal blamed this year's stiffer opposition within the committee on intensive lobbying by business. Only two of the committee's 14 Republicans, Frank Horton (N.Y.) and Joel Pritchard (Wash.), voted for the bill.

Later in the day, the Senate Governmental Affairs Committee approved a similar measure with little ado, by a vote of 10 to 2.