Israeli diplomats are coming round to the idea that the White House could try to impose its own peace plan on the Israelis and Palestinians for the first time in four decades.

In addition to reports by well-sourced correspondents in the American media, there have been a number of signals in recent days that the administration is planning to present its own peace plan. The next visit to the region by US representative George Mitchell has been repeatedly postponed, giving rise to the speculation that President Barack Obama has decided to change tack.

In addition, the Americans are no longer insisting that PM Binyamin Netanyahu provide a swift answer to their demands on settlements and other subjects as a prelude to a renewal of talks with the Palestinians. This is seen as another indicator that the Americans do not believe that Mr Netanyahu can currently deliver an answer and that a more radical approach is called for.

The last time an American administration tried to impose its own solution was in 1969, when Secretary of State William Rogers presented Israel and Egypt with a framework for ending the hostility between them. Israel refused to accept the Rogers Plan and, ever since, the American approach has to been to try to get the sides to sit down with each other and help them reach a peace agreement. A number of Obama advisers are apparently telling the president now that it is time for him to take up Mr Rogers's torch.

The Obama peace plan is still being worked upon but it is widely supposed to resemble the "almost agreement" that the sides were close to at the Camp David conference a decade ago. This provided for a Palestinian state on the almost the entire West Bank, a partition of Jerusalem with joint rights in the Old City and Temple Mount and creative solutions for the Palestinian refugee problem.

While polls show that a majority Israelis would support many of these ideas, they are anathema to almost all parties in Mr Netanyahu's coalition. Sources close to the PM said that "we will not be forced into accepting any imposed solution. If the administration tries that, it will ultimately fail."

But one adviser admitted that in the end it will depend on the amount of pressure the Americans apply.

"If they create a clear linkage between the plan and their continuing strategic support, Bibi will find it very difficult to say an outright no, especially if, as expected, the Americans continue to connect the Palestinian and Iranian issues."

Mr Netanyahu was scheduled to attend the Nuclear Security Summit in Washington this week but backed out last minute. The ostensible reason was the expected attempt by Arab states to bring up Israel's nuclear capabilities but diplomatic sources have admitted that Mr Netanyahu is anxious to postpone high-level dealings with the administration in which the Americans may press their Israeli counterparts for answers on the peace process.