The markets last week looked on at the commitments made by the finance ministers' meeting in Brussels to strengthen the defences of the euro amid a growing belief that not only Portugal will follow Ireland into Klaus Regling's bailout facility, but Spain too.

More and more analysts now predict that, after the Christmas trading lull, sovereign debt markets will again test Portugal's ability to resist the need for European and IMF emergency funding.

The trapdoor, analysts say, will probably open when Lisbon goes looking for the €11bn it needs to fund the country in the first three months of the year and the €12bn it will need in the second quarter.

Portugal is already taking the strain as borrowing costs remain at elevated levels.

The annual interest rate for Lisbon to borrow for three years was trading last week at 4.7%, close enough to the 5.2% rate Greece is paying for its emergency money for the next three years.

Lisbon's interest rate on 10-year borrowings was trading little changed last week at 6.27% – the level which the equivalent Irish rate had reached on 20 October after the NTMA had been forced to cancel its costly debt auctions. Last week, Bank of America economists predicted Spain would require said funding in the first half of the year, probably sometime after Portugal.

A debt auction last week in Spain which led to a jump in the cost of its borrowing for 10 years to 5.44% showed that pressure was building on Madrid too. Is there enough money to rescue Ireland, Portugal and Spain in the European facilities? Yes, says Bank of America, if Spain were to stay out of debt markets for only two years. That would get Spain through 2013 – by which time the new euro support mechanisms are due to be be in place.