New Trouble on Set of Thatcher-Kohl Show : Europe: She reveals West German’s secret thoughts on the Polish border issue. Infuriated, he denies everything.

The on-again-off-again political romance between British Prime Minister Margaret Thatcher and West German Chancellor Helmut Kohl was off again Monday--at least temporarily.

The two West European leaders, who are scheduled to meet Thursday and Friday in Britain to patch up differences over the desirability and speed of German reunification, are suddenly involved in another public row.

Over the weekend, Thatcher gave a series of interviews to the West German media--as did Kohl to the British press--to attest to their friendship, a relationship both see as central to the fate of Western Europe.

In statements to the newsmagazine Der Spiegel of Hamburg, Thatcher disclosed Kohl’s private thoughts on the German-Polish border issue that she said he expressed during their last meeting in December at a European summit conference in Strasbourg, France.

She asserted that Kohl had said he did not recognize the current Polish border with East Germany. This is a subject on which he subsequently waffled in public, attracting widespread international criticism before he expressed support for the present borders.

Specifically, according to Der Spiegel, Thatcher said: “I’ve heard Helmut say, ‘No, I guarantee nothing, I do not recognize the present (German-Polish) borders.’ I heard it myself after the dinner in Strasbourg.”

After learning about Thatcher’s reported remarks, an infuriated Kohl sent his press spokesman, Hans Klein, before the media Monday to deny all.

“The quote attributed to him is neither literally correct,” said Klein, nor did it in any way reflect the content of any remarks made by Kohl in Strasbourg.

As to how Thatcher might have misunderstood Kohl, Klein said flatly, “This question should be put to Mrs. Thatcher.”

Thatcher further irritated Kohl by criticizing his legalistic view that only a united Germany could sign a treaty with Poland guaranteeing the present borders.

She stressed, according to Der Spiegel, that only an international treaty with Poland could be accepted, declaring, “You know what happened to such assurances in the past--West German courts overturned them.”

Klein said that comment was “unfounded and unusual.”

Other parts of the interview reflected her view that Britain must respect German unity.

“We have to get used to the idea that there will be a country in Europe that is stronger than all the others. We cannot always be thinking about how to create a counterweight to Germany.”

Kohl and Thatcher have had differences in the past, and these invariably have been underscored in leaks to the media by their public relations people.

They were quite compatible at first: two staunch conservatives aided by the third member of a Tory triangle, former President Ronald Reagan. But things soured.

Thatcher, her people say, believes that she can never get a straight answer out of Kohl and, even then, he takes too long to say nothing. Kohl, his advisers say, believes she is an arrogant, abrupt official who has no idea of the difficulties facing Continental politicians--like himself--who govern through coalitions and are forced to compromise to stay in office.

Earlier stories emanating from their respective spokesmen had indicated that the Thatcher-Kohl disagreement over the pace of German unification would be patched up Thursday, when they both speak at an Anglo-German meeting in Cambridge, and Friday during their scheduled private meeting in London.

And, despite the current fracas, political observers say that after their Friday reunion in London, all will once again be sweetness and light--at least through next weekend.