(Adds demonstration in Madrid, previous BORDEAUX, France)

MADRID, Dec 4 (Reuters) - Thousands of Spaniards demonstrated against ETA on Tuesday after gunmen from the guerrilla group shot two policemen at the weekend, killing one of them and making Basque separatism a major election issue.

Politicians of all colours and their supporters, carrying Spanish flags, gathered in central Madrid but were deeply divided in their opinion of how the Socialist government of Jose Luis Rodriguez Zapatero is dealing with ETA.

"Zapatero, you're not alone," shouted one group. Others criticised the government for holding peace talks with ETA last year before they blew up a car park at Madrid airport last December, killing two, and called off a truce this June.

"The government has made a pact with ETA and that's why they're not here," said Ana Bonilla, a financial markets trader.

Zapatero stayed away from the demonstration, having earlier flown to France to the bedside of Fernando Trapero, 23, who is fighting for his life after being shot at point blank range on Saturday. He and his colleague Raul Centeno were shot when they crossed paths with ETA members at a cafe near Biarritz.

"I join in the same feelings that all Spaniards feel who are thinking of Fernando, who has been hurt so savagely, so unjustly, so intolerably," Zapatero told reporters.

Zapatero was booed at Centeno's funeral on Sunday as ETA's first killing in almost a year awakened memories of his failed attempt to negotiate peace with the separatists, who have killed more than 800 people in four decades.

Zapatero is due to call elections by March 2008 and while the economy, slower growth and a potential drop in house prices had been shaping up as major battlegrounds, the weekend shooting has pushed ETA back up the campaign priority list. (Writing by Jane Barrett; editing by Elizabeth Piper)

AlertNet news is provided by