TO WATCH: 2:15 Raw violence Video
Both sides are arguing over the effectiveness of a 24-hour strike...led by Spain's 2 biggest unions.
Unions claim 900,000 protested in Madrid...and 800,000 in Barcelona.
But 156 were arrested...as much public transport and some factory production slowed.
At least 58 police were injured...and 46 civilians.
Most of the violence occurred in Barcelona.
Whatever the actual number of protesters...conservative PM Mariano Rajoy pushed thru labor law changes...in an effort to reduce the nation's stubbornly high unemployment rate of 24%...and 50% for those under 25 years.
Now he has also revealed the exact pain from 2012 budget cuts : E27bn /$36bn.
But the cuts are less than some economists predicted.
Rajoy's party was recently denied a majority...in a surprising regional defeat...as austerity measures gain traction...and fuel anger.
"This is the largest cut of (workers') rights since anyone can remember. There has to be a better way to get out of this crisis," said a union worker.
The always hungry 'markets'...looking for high yields...and seeing the turmoil...are now weighing Spain's default risks...sending its 10 year bond yield rising to 5.46%...surpassing formerly beleaguered Italy's 5.089%.
TO READ: More On Budget Cuts: