LONDON — The weekend plan to rescue Spain’s ailing banks was supposed to boost confidence in Spain and the other 16 countries that use the euro. The skeptics said it would provide only temporary relief for the markets. In the end, it barely did that.

Stocks and bonds surged in the first hour of trading Monday, a knee-jerk reaction to the weekend news that Spain would funnel to banks up to $124.7 billion in loans from its euro partners. But hours later, stock prices were back down, government borrowing costs up, and bad economic news piled up across Europe.

Spain

Financial markets temporarily showed signs of relief that Spain’s banks would receive an infusion of money. The country’s main stock market index initially jumped nearly 6 percent and the government’s borrowing rates fell sharply.

Spain is in its second recession in three years, a quarter of its workforce is unemployed, and home prices keep falling, making banks even weaker.

By the end of the day, Spain’s Ibex stock index finished with a 0.5 percent loss. The interest rate on the country’s 10-year bonds rose to 6.47 percent, a sign of investor nervousness about lending to Spain.

Italy

Once it became clear that the rescue money for Spain’s banks would not solve that country’s problems, investors began worrying about one of its euro partners:Italy.

Italy’s economy is larger than Spain’s. Its banks are in better shape. But like nearly half of the countries in the ­euro, its economy is shrinking, making it difficult for the government to chip away at a mountain of debt.

Italy released data Monday that confirmed the country is in recession and has little likelihood of a big recovery this year.

Cyprus

Cyprus, which has the 15th-smallest economy in the eurozone, acknowledged Monday it was considering applying for an emergency loan package for its banks similar to the one Spain sought.

If it did ask for a European loan, Cyprus would become the fifth country in the currency union to seek outside financial help.

The government’s finances are in decent shape and the economy is not in recession. But Cypriot banks were heavily exposed to Greek government debt. They took huge losses when Greece wrote off about three-quarters of the value of its bonds.

Greece

The greatest uncertainty hanging over Europe this week is Greece, which holds a national election Sunday.

A political party that has a real chance of winning, the radical left-wing Syriza, has campaigned on a plan to refuse to live up to the terms of the country’s $170 billion international aid package.

If it were to do so, Greece could lose access to the money that is keeping the government solvent and be forced to leave the euro.