Jordan's King Hussein said here tonight that there was "no truth at all" in allegations by the Palestine Liberation Organization that last-minute changes had been made in the wording of a statement Britain said two PLO delegates had agreed to endorse in London yesterday.

But he acknowledged that one of the PLO representatives, former West Bank mayor Mohammed Milhem, "was not aware, apparently, of the details" in the statement, negotiated by Jordan on the PLO's behalf, until it was shown to him here Sunday night before a meeting scheduled for yesterday morning with British Foreign Secretary Geoffrey Howe.

Milhem's refusal to endorse the document, the condition Britain had set for its talks with the PLO at the highest level yet, led to Howe's abrupt cancellation of the meeting with the joint Palestinian-Jordanian delegation. Milhem and Britain confirmed today that Milhem had objected to the explicit mention of Israel in a portion recognizing the right to peaceful existence of all states in the Middle East.

That wording went beyond more general references in U.N. resolutions that sources here said Milhem asked be substituted. They said that Milhem, after consulting Sunday night with PLO Chairman Yasser Arafat, had asked for a postponement of the meeting but that Howe had refused on grounds that Jordan had given "unambiguous assurances" that the PLO had agreed to the wording.

Milhem had not seen the statement that was agreed upon by British and Jordanian officials last week in Amman. But officials here said his fellow PLO Executive Committee member and delegate to the talks, Anglican Bishop Elia Khoury, was aware of the statement.

Milhem said today that he believed Britain had not wanted the talks to succeed and that Howe's insistence on the offending wording was "intended to undermine the whole attempt for a peaceful settlement."

Hussein, who arrived here today on what was described as a private visit, said in a television interview that Jordan had nothing to "complain about" regarding Britain's behavior. "If there is a misunderstanding in terms of one member of the Palestinian delegation not having been aware of what was happening, that is certainly neither our fault nor anyone else's fault," he said.

"We will have to reassess our positions, look at the problem once again with the PLO, with the Palestinian people, with others, and see what went wrong and how it could be corrected."

He rejected suggestions that he may have moved too quickly in trying to advance the peace process. "I think the crowning achievement of my life would have been and will be the establishment of a just and durable peace in our area," Hussein said, "and I don't think it is fast enough in coming yet."

Later today, Hussein told the British Broadcasting Corp. that he hoped his peace initiative "has not ended; the alternatives are frightening." He added that he also thought the United States "has not lived up to our expectations" in the matter.

Dennis Healey, foreign affairs spokesman for the opposition Labor Party, today accused the government of Prime Minister Margaret Thatcher of causing "an appalling diplomatic shambles."

He accused Thatcher of bowing to heavy pressure from the Reagan administration to scuttle the talks, a charge both Hussein and Howe denied, saying that there had been no such pressure.

On Sunday, the Palestinians, Jordanian Foreign Minister Taher Masri and Deputy Prime Minister Abdul Wahab Majali, met with British officials to go over the statement to be issued by the joint delegation following the meeting with Howe.

According to all accounts, Milhem and Khoury agreed to the portion of the statement renouncing violence. Khoury reportedly was willing to endorse the explicit reference to Israel, but Milhem refused.

Milhem contacted Arafat, sources said, and it was agreed that the PLO would ask for the meeting to be postponed if Britain would not agree to change the wording.

When Howe was told of this yesterday morning, however, he canceled the meeting.

Malcolm Rifkind, Howe's chief deputy, said today that "at no time did President Reagan or any other American official or minister or anyone else in the United States ask the United Kingdom to reconsider the visit that was proposed."