Venezuelan authorities on Thursday denied permission to a group of visiting Spanish senators to meet with a former mayor who is being held at the Sebin intelligence agency headquarters.

"We would have liked to be able to go in, since that is what we came for, but we're not going to make any kind of criticism regarding the decisions (the authorities) are taking. We're respectful. We came here with the intention of seeing Daniel (Ceballos)," Sen. Dionisio Garcia, a member of Spain's governing Popular Party, told reporters.

Garcia and three colleagues - from three different parties - waited for two hours for authorization to enter the Sebin HQ in Caracas, but when that was not forthcoming they left.

The senators were accompanied by a delegation from the Venezuelan opposition MUD alliance that included the wives of detained political opposition figures Antonio Ledezma and Leopoldo Lopez, Mitzy Capriles and Lilian Tintori, respectively.

"We're going to be here tomorrow and we haven't lost confidence (that we'll be able to visit Ceballos) and if at some time they tell us that we have authorization, then we will (do so)," Garcia said.

The senator said that "it would have been nice" for the lawmakers and "for (Venezuela's) own image" for them to have visited Ceballos.

The former mayor was sentenced more than a year ago to 12 months in prison for failing to heed a Supreme Court ruling but, after he completed that sentence, the high court announced that he would remain imprisoned on another legal matter involving rebellion and criminal conspiracy.

In addition, the Venezuelan General Comptroller's Office on July 6 banned the former mayor from holding public office for 12 months, a decision that would prevent him from being a candidate in the Dec. 6 legislative elections.

The Spanish senators are also scheduled to meet on Thursday with representatives of Venezuela's Catholic bishops conference and with student leaders from the country's main universities.

On Friday, they will try to visit Lopez, who has been imprisoned since February 2014 and stands accused of crimes linked with violence that broke out during an anti-government protest.