Virginia Lt. Gov. John N. Dalton, escalating his attacks on Democrat Henry E. Howell, yesterday charged Howell with changing positions on key issues in different parts of the state, "virtually flip-flopping on every issue" in their race for governor.

It was the Republican's harshest criticism of Howell to date and came as an independent conservative group previewed anti-Howell television commercials which call the populist candidate "too radical, too erratic to be governor."

The three commercials are scheduled to be broadcast only in Richmond and Roamoke.

Campaining in Northern Virginia, Dalton disavowed any prior knowledge of the commercials and their content but in speeches and broadcast interviews yesterday, he appeared to be doing what the conservative group has publicly suggested he should do: abandon the caution he has previously shown in attacking Howell.

"I consider him to be the most inconsistent candidate that has ever run for governor in the Commonwealth of Virginia." Dalton told one television interviewer during a morning stop at an Alexandria retirement home. Repeatedly during the day Dalton accused Howell of advocating higher taxes on upper and middle income families, dropping some of the qualifications he has previously expressed in discussing the issue.

Dalton turned aside reporters' questions as to whether he was beginning a "negative" campaign against Howell. He said, howevee, that he intends to "emphasize" what he called Howell's "inconsistences" and "flip-flops" during the past 12 years that Howell has been a major Virginia political figure.

As he toured the Washington suburbs, Dalton consistently said Howell supports higher income taxes on wealthy families despite Howell's claim that he would veto any "general" tax increase.

Although Dalton has said the tax issue is central to his Northern Virginia campaign, it is not the only alleged inconsistency that he says he will stress in thedays before the November 8 general election. He said Howell has been inconsistent in his opposition to gun control laws, collective bargaining of public employees, the Virginia right-to-work law and "many other things."

Howell has denied the charge of inconsistency repeatedly.

While Dalton was escalating his attack, he backed away from a charge made Thursday in a Richmond speech, that Howell "once labeled every American businessman an embezzler from the American consumer." At an Alexandria breakfast meeting with 35 campaign workers, Dalton said Howell had called "the big boys" embezzlers in a 1972 speech.

Howell has vehemently denied making the statement that Dalton attributed to him originally, and a Dalton spokesman yesterday conceded that Howell never used the word "businessman."

Dalton press secretary Richard Lobb said, however, that Dalton madd a "reasonable inference" when he said that the "big boys" represented "every American businessman." Then Lobb admitted some uncertainty over what Howell means by "the big boys," a phrase he has used frequently since his first race for governor in 1969.

For the most part, Falton was well received during his Northern Virginia stops yesterday. "We're religious folk," said Madison Coe, an 83-year-old Federal Reserve Board retiree and one of the residents of a Methodist Church retirement home who turned out to hear Dalton yesterday. Coe said he was troubled by Howell's action in Petersburg Wednesday, when he sand a campaign song of the tune of "Jesus Loves Me." It is a song that Coe, son of a minister, described as "one of our best religious hymns - it just doesn't go too good with me."

In Richmond, the group mounting the anti-Howell campaign, the Independent Virginians for Responsible Government (IVRG), previewed its television spots for reporters.

The ads portray Howell as "soft on the right to own firearms," unwilling to defend the state's ban on compulsory union membership; willing to accept "unionization of policemen and certain to "cost Virginia jobs and money."

Howell declined to comment on the ads at a press conference at which he charged that the Virginia Conservative Political Action Committee (VCPAC), which helped launch IVRG with a $2,990 loan, was guilty of a law violation because of its failure to list the National Conservative Political Action Committee (NCPAC) as an affilitated organization when VCPAC filed its organization papers with the State Board of Elections.

Shortly before Howell talked to reporters, VCPAC filed amended papers listing the NCPAC affiliation. Its organizers had previously identified VCPAC as a project of the national organization. They told Election Board Secretary Joan S. Mahan in a letter that they thought the organization form only required listing of affiliations with other state or local organizations.