One proposal concerns expanding the European Court of Justice's role in monitoring budgets and punishing members running up deficits, the weekly magazine reports in the issue to be published Monday. According to Der Spiegel, Merkel has advocated a meeting of heads of state and government "to set a new legal basis for the EU."

Merkel would like to see such a meeting by year's end. Der Spiegel reports that "at an informal gathering of 10 foreign ministers, a majority rejected the idea of such a meeting" when German Foreign Minister Guido Westerwelle suggested it.

The magazine quotes her European affairs advisor, Nikolaus Meyer-Landrut, as saying that under Merkel's plan, a committee would lay the groundwork for the new treaty. The treaty would broaden the existing fiscal pact's authority in the political union. As a result, individual nations' authority over their own finances could be diminished.

"There are also steps to integration that will require changes to the (existing EU) treaty," Merkel said in May. "We have not got that far yet, but there should be no taboos."

Bundesbank 'drug' warning

Weidmann has repeatedly warned against the ECB's bond buying

In another Spiegel interview released on Sunday, Bundesbank chief Jens Weidmann warned against the European Central Bank's plan for a new program to buy up government bonds of debt-stricken eurozone members.

Weidmann told the magazine that the bonanza provided by central banks "would give rise to long-term avarice."

"We should not underestimate the danger that central bank financing can create addiction, like a drug," he said. "In democracies, it is parliaments and not central banks that should decide upon such a comprehensive pooling of risks."

Danger to ECB's independence

ECB President Mario Draghi is expected to lay out the bond-purchase scheme after a meeting of the bank's 23-member Governing Council on September 6.

Der Spiegel said Germany's finance ministry is worried that the new plan could endanger the bank's independence.

As a condition for ECB support, a country will first have to seek an aid program from the eurozone's bailout funds. This is subject to approval by finance ministers, and central bankers are concerned that this would make their action dependent on politicians.

The ECB has been forced to intervene more forcibly as of late to help combat the eurozone debt crisis, as the bloc's governments work to overcome legal and political hurdles obstructing a coordinated long-term response.

tj,mkg/slk (Reuters, dpa, AFP, AP)