Virginia Gov. John N. Dalton said today his opposition to a special Metro tax remains firm and unequivocal, thus quashing suggestions by some Northern Virginia legislators that he has an open mind on the issue.

Since last Wednesday, when Dalton announced in a speech to the legislature that he opposes such taxes, these Northern Virginians have insisted that Dalton would consider their proposals only if the assembly would pass them.

In an interview in his State Capitol office today, the Republican governor said he was baffled by such claims. "I don't know how I can be more explicit," he said "I oppose an increase in the sales tax."

Dalton's latest statement on the Metro sales tax proposal came amid conflicting reports from some Republican legislators about the governor's true intentions toward a bill that would add a one cent increase to the current four-cent sales tax in the Washington suburbs.

"He did not say he was going to veto it," said Del. Martin H. Perper (R-Fairfax) on Tuesday after he met with Dalton. Perper said then he came away with the feeling that Dalton "has an open mind" on the tax measure.

Perper and Del. Vincent F. Callahan Jr. (R-Fairfax), who also attended the meeting with Dalton, said afterward they still had reason to hope that the governor would sign the sales tax bill if it passes the assembly.

Most of the 23 legislators in the Northern Virginia delegation are supporting the measure.

Del. Gary R. Myers (R-Alexandria) said he also met with Dalton last week on the sales tax issue and was completely convinced the governor will veto the bill. "I'll still work for it, but I don't think the governor will sign it," Myers said.

Itnerjected into all this speculation was Perper's suggestion that Dalton "was unaware of what the present bill contains" when he announced his oppostion. "It's different from last year because it has [provisions for] a referendum."

The measure requires voters in all three Virginia cities and both counties served by Metro to approve the sales tax in their localities before it could become effective in any of them.

Dalton said today, however, that he understood all elements of the bill at the time of his speech to the assembly.

"... The referendum doesn't make any difference," he said. "I think most of the people of Virginia are looking to us to keep a uniform sales tax and uniform income tax, and that's what I'm trying to do."

Stressing that his sales tax position is consistent with his 1977 campaign statements, Dalton said that making an exception for Northern Virginia could result 'in a hodgepodge of sales tax increases around the state."

Supporters of the sales tax measure say Northern Virginia's Metro situation is unique and that the area needs an alternative revenue source to meet the transit system's costs without sharply raising property taxes.

"People opposed to Metro are going to have to pay for it anyway," say Callahan, adding that the sales tax measure is the delegation's attempt to spread the tax around equally and to share the burden with all, even tourists.

Faced with contradictory remarks by Northern Virginia lawmakers, Dalton said today he "should get Callahan and Perper up here and make my position clear." He did, indeed, summon the two delegates to his office.

Perper said later that he would stand by his previous statement about the governor's open mind, but Callahan said "the implication of a veto is there."

Still, Callahan and Sen. Wiley F. Mitchell (R-Alexandria) continued to hold out hope that the governor would change his mind.

"I think we should quit worrying about what the governor is going to do and get the bill passed," said Mitchell. "It's important to us as Northern Virginians, and it's important to us as Republicans working with a Republican governor. I am optimistic we will be able to get the governor to sign the bill. I really am."