In Hungary alone, where an economic recovery has faltered recently, about 700,000 homeowners hold mortgages and others loans that were borrowed in francs when the Swiss currency was weaker. A stronger franc makes those loan payments more expensive. Alarm is growing, and Hungary’s financial market supervisory authority warned Thursday that large numbers of foreign currency loan holders would be late with repayments.

Despite Swiss authorities’ efforts to stem the franc’s surge, recent actions — including cutting interest rates close to zero last week and raising the supply of cash in the franc money market this week — have practically fallen into a black hole.

A peg to another currency is considered anathema to many Swiss, who have prided themselves on not joining the European Union, not to mention the euro monetary union, which they believe would only weaken the nation over time.

In any case, a peg would require changing the Swiss constitution, which has regulated the currency since 1850. And it would mean the Swiss central bank would risk ceding some of its independence to the European Central Bank, which manages the euro. It was also not immediately clear how a peg would be adopted at a technical level.

A euro peg “is certainly not the easiest plan to put in place, either politically or legally,” Mr. Danthine acknowledged.

Business people and Swiss citizens would also be loath to see their cherished currency linked to a European monetary union gripped by crisis.

Pegging the currency would be “a big risk,” Thomas Christen, the chief executive of Reed Electronics, a Lucerne-based company, said in a recent interview. “Then you can’t move; you are not free and our reasoning in Switzerland is to be free in these decisions.”