MADRID — Princess Cristina, King Juan Carlos’s younger daughter, was named as an official suspect in a Spanish court investigation of corruption allegations centered on her husband’s business activities.

Judge Jose Castro at the regional court of the Balearic Islands ruled that the princess, suspected of tax evasion and money laundering, should give evidence on March 8, the court said in a ruling sent by email Tuesday. A spokesman for the royal family declined to comment.

Pressure is increasing on the Spanish monarchy, which has seen its public support decline amid the corruption investigation, as the ailing King struggles to carry out his duties.

Cristina’s husband Inaki Urdangarin, a former Olympic handball player, is a suspect of fraud, embezzlement and money laundering in the probe that focuses on the nonprofit Noos Institute he chaired.

The institute won 5.8 million euros ($7.9 million) of contracts from the regional governments of Valencia and the Balearic Islands between 2004 and 2007 without participating in a competitive tender, ABC newspaper reported.

Cristina was previously named as a suspect in April last year before that ruling was overturned following opposition from the public prosecutors.

Support for the monarchy as a system of government in Spain fell to 49.9 percent in December compared with 53.8 percent a year earlier, according to a Sigma Dos poll of 1,000 people published Jan. 5 in El Mundo newspaper.

Juan Carlos should abdicate in favor of his son Prince Felipe, 62 percent of respondents said.

The 76 year-old King hesitated and stumbled repeatedly when reading an address to military chiefs Monday. The speech was Juan Carlos’ first public appearance outside the palace since undergoing a hip operation in November.