Rep. Phil Gramm, who was denied his seat on the House Budget Committee by fellow Democrats on Monday, returned to Texas today and is expected to announce Wednesday that he will resign his House seat and seek reelection to Congress as a Republican.

The Democratic House leadership, anticipating that Gramm will shift to the GOP, yesterday went out of its way to minimize his claims to martyrdom. At the same time, the House Republican leadership opened its collective arms to welcome Gramm into the party.

Rep. Robert H. Michel, (R-Ill.), the minority leader, announced that the GOP Committee on Committees decided to reserve a Republican seat on the Budget Committee for Gramm.

Michel attacked the Democratic leadership decision to take Gramm's Budget Committee seat away as "a grievous assault on the right of an individual member to represent the views of his constituents as honestly and openly as possible. . . . We are ready to give him and his constituents the opportunities they deserve."

Rep. James C. Wright Jr. (D-Tex.), the majority leader, held a news conference to stress the argument that taking Gramm's seat on the Budget Committee was not a penalty.

"Denying a person a reward (service on the Budget Committee) is not a punishment," he said. Wright described the position as "a prize, it is a plum, it is a leadership assignment . . . . A person is not excommunicated from the church if he is not elected to the board of deacons."

Later in the day, the Democratic Steering and Policy Committee pointedly put off a decision whether to take from Gramm his seat on the Energy and Commerce Committee, a key panel for a representative from an energy-producing state.

The delay was designed to deny Gramm further ammunition to justify jumping from the Democratic Party to the GOP.

Democratic leaders prepared to nominate a freshman Texas Democrat, John Bryant, to replace Gramm on the Energy and Commerce Committee if Gramm switches parties. This would prevent Gramm from claiming that the House leadership eliminated Texas representation on the Energy and Commerce Committee.

As Gramm flew from Washington to his congressional district in east central Texas for a Wednesday noon EST news conference, Republican Party officials and Gramm's political advisers began to prepare for a special election campaign if he resigns.

Texas Democrats said today the timing of a special election could make it difficult to field a strong challenger to the maverick "boll weevil," whose advocacy of President Reagan's economic programs led to his ouster from the Budget Committee.

A number of Democrats said that Gramm, who already has $207,000 in campaign funds, would be hard to beat in a special election, and suggested that if Gramm switches it would be only for the extra publicity he would receive. "It won't be a mandate for anything," said one.

Several Democrats said attempting to defeat him in 1984 might be more sensible. "If you're going to fight a battle, let's fight it on your own ground," said one party leader.

Two of the strongest potential challengers to Gramm said today they will not run against him if he resigns his seat.

State senator-elect Chet Edwards, who narrowly lost to Gramm in a 1978 primary and is perhaps the strongest Democrat in the heavily Democratic 6th Congressional District, said he would not rule out a future race against Gramm, but that he is not prepared to run now. State senator Kent Caperton said he has no desire to leave the Texas Senate and ruled out a challenge.

Jack Teague, who lost badly to Gramm in the Democratic primary last spring, said today he does not know whether he would run in a special election. He is the son of former representative Olin Teague, whom Gramm succeeded in 1978.

Some months ago, Gramm hired Republican pollster V. Lance Tarrance of Houston to help him prepare to switch parties if the Democrats knocked him off the Budget Committee. Tarrance polled the district and reportedly told Gramm that he could win back his seat as a Republican, although it might be difficult.

Some Republicans in Texas were said today to be nervous about Gramm attempting to win election as a Republican now because of the drubbing Republicans took here in the November elections. And Democrats in Washington said they still are not convinced that Gramm will quit his seat, predicting that he might simply jump to the GOP and seek reelection in 1984.

But Gramm already has signed up Republican political consultant Fred Allen to run his campaign. Allen is a former associate of White House political adviser Lee Atwater, with whom Gramm met on Monday to discuss his plans.

The timing of a special election remained unclear today. A special election must be held no less than 20 and no more than 90 days after a vacancy occurs, according to Texas law.

If Gramm resigns and runs as a Republican, he would be the first House member to resign in the middle of a term and then run in a special election under a different party since Rep. Albert Watson (S.C.), who was elected as a Democrat in 1962 and 1964, resigned in February, 1965, and was elected as a Republican in a special election the following June.

Staff writer Thomas B. Edsall contributed to this report.