The euro has come under in the recent trading sessions due to ongoing uncertainty over debt crisis in the region, but investors await ECB meeting Thursday, which could provide some relief to the single currency.

ECB meetings are eagerly-awaited events, not so much for the decisions taken on rates, which are often expected, but for press conference content, which is where Jean-Claude Trichet can surprise the markets, said Societe Generale (SG) in a note.

While the consensus is 25bp increase in key rates by ECB, hawkish press release highlighting strong vigilance on inflation and no particular concerns with the euro debt, would significantly underpin the EUR.

“The market will also be watching for comments that the ECB may decide to no longer be contingent on agencies’ ratings. Such comments would remove at least some of the uncertainty from the mix and boost EUR today,” said SG.

“Given uncertainty on external factors, ECB’s President Jean-Claude Trichet is unlikely to discuss the short-term monetary outlook. In this scenario, the ECB meeting would have a relatively neutral impact on the EUR/USD,” it added.

EUR/USD fell to a session low of 1.4291 on Thursday after Moody's ratings agency downgraded Portuguese banks' govt-guaranteed debt after it had cut the country's credit rating the previous day.

The rating agency on Tuesday downgraded Portugal’s credit rating by four notches from Baa1 to Ba2, citing growing risk of second round of aid for the country.

EUR/USD still remains in the broader 1.40 to 1.50 range it has been in since mid-March, but it is again threatening the 100-dma at 1.4259, with the ECB on deck overnight, RBC Capital Markets said.

Trichet is likely to rein in hawkishness as tends to occur when the ECB has just hiked rates. Beyond that the market will be particularly attuned to signs of whether the ECB is poised for a prolonged pause (anything that smacks of less than a quarter per quarter). If the market detects heightened concerns, the 100-dma will be challenged, if it hadn’t been already, RBC said.

However, the biggest downside risk for the euro from today’s ECB meeting would be the central bank keeping the rates unchanged.

“In such a scenario, a market reaction similar (or even higher) to that of May would then be possible with 1.3970 in the crosshairs,” SG said.

The other risk would be a dovish press release with a rate hike, which could take the form of an uncertain economic outlook owing to the uncertainty of external factors.

Given market positioning, this could add to downside pressure on the EUR/USD. Breaking the support at 1.4275 would open the door to all-time lows for the week at 1.4105, SG added.