Declaring the Redskins' final offer to be "shocking and insulting," the agent representating running back Mike Thomas said yesterday negotiations between the club and his client have reached a major impasse.

"We were given an ultimatum by the Redskins, which, in effect, the Redskins have asked Mike Thomas to play out his option," said agent Guy Draper. "The offer that was put to us as a final offer was quite embarrassing."

Draper declined to reveal specifically what that final offer was, other than to confirm that "it was in the general area" of 2 1/2 ties Thomas' current salary of $28,000 a year. That would make the offer in the $70,000 range.

At workputs for the Pro Bowl last month, Thomas told Dave Brady of The Washington Post he would be general area" $28,000 a year. That current contract. Draper said yesterday "that (Thomas' statement) was not accurate."

The Washington Post stands by its original story.

Draper also declined to reveal how much his client was asking from the Redskins, other than to say "It's substantically more than that ($70,000).We are looking for security for Mike.

"The player's" union says the average life of a football players is 4 1/2 years, and less for a running back. This will be Mike's third year and, by those figures, he has played three fourths of his career at poverty wages.

"Mike was rookie of the year, he has averaged 1,000 yards a year his first two years and they're treating him as though he's a reserve running back."

Draper said he received the Redskins' offer on the telephone from team president Edward Bennett Williams on Jan. 21, the day the first round of negotiations between the club and the agent were scheduled.

Draper said he sent William written notice yesterday that "Mike has rejected the final offer and that I an requesting an immediate meeting for them to begin bargaining in good faith. I've been talking with them since last may, and it's all been in bad faith."

Williams was not available for comment.

Draper said he also understood that Willie Spencer, former WFL and Viking full back signed last month by the Redskins, "is being paid three times what Mike is now making. There's too much discrepancy in what Mike is making and what others are making."

Draper said Thomas was the lowest paid Redskin starter in 1976, the second lowest paid player on the entire roster and played last year for less than he did the year before.

Under the option clause in his current contract, Thomas would be obligated to play next season with the Redskins, then would be free after May, 1 1978.

"I would hope it wouldn't come to that," Draper said. "I'm confident the Redskins will reassess their posotion. If not, playing out the option will be one of the alternatives.

"You know we had some bad experience last year (29 Redskins went to training camp unsigned) and it hampered the performance of the team. It's inconceivable to me they would do it again. But year after year I become more suprised by the condust of management in the NFL."

Two of Draper's other Redskin clients, receivers Frank Grant and Larry Jones, also are have contracts running out. Draper says he has not begun negotiations for those players,

"But I was told by one very high official of the Redsakins that Frank Grant had a lousy season. If that's any indication, we could have another problem."