The F1 supremo angered the region's incumbent leader Francisco Camps' opponents this week when he announced that the contract for a street circuit grand prix would only be signed "when Mr Camps wins" at the polls later this month.
Spain's Deputy Prime Minister Maria Teresa Fernandez de la Vega reacted that "these are lamentable, unfortunate and worrying statements."
Camps has reportedly pledged more than $30 million a year to obtain the rights for a race.
"This is a means of blackmailing the electorate," said Camps' Socialist rival in Valencia, Joan Ignasi Pla.
Ecclestone was embroiled in another political storm ten years ago when he donated $2m to Britain's Labour Party, which had to be returned following similar criticism.
The 76-year-old F1 supremo explained in Barcelona on Friday: "I said I wouldn't formalise a contract until after the elections because I didn't know who I would be signing it with."
Previous: Valencia's place on the 2008 Formula One calendar is expected to be revealed to the world with a media conference on Thursday.
The governor of the autonomous Spanish region, Francisco Camps, will appear alongside F1 supremo Bernie Ecclestone in the city, where a street race is to be announced, according to the Spanish newspaper 'Marca'.
It is not expected that the race is a threat to Spain's existing grand prix in Barcelona, and some sources even suggest that the Valencia event could be staged only once every two years.
Meanwhile, the feature of the 4.3km circuit - which has been designed by Spanish engineers with input by Hermann Tilke - is a temporary bridge, which will link the two sides of the Valencia port.
Valencia F1 deal for 2008 signed - report
A definitive deal for a new formula one street race in the Spanish city of Valencia has now finally been signed.
That was the claim on Wednesday of the private radio network 'Cope', which said Bernie Ecclestone's circus would race at a second Spanish venue next year.
It is suggested that the existence of the contract could be announced by the F1 supremo at Barcelona as early as during a press conference on Thursday.
The descriptor 'European Grand Prix' is tipped to be used, as it will be free because of the rotation of F1's two German venues.
Next year's Hockenheim event, following the race at the Nurburgring in 2007, will instead be called the German GP.