Then you renegotiate in a proper way, not hold the nation's children as ransom.
Any other job you would sit down with your boss and talk over it, if you don't like it, you quit and find something else. What you don't do is sit and home and not go to work, or worse still, stand outside the office with a banner and chanting ! It is terrible etiquette if you ask me.
The government (Gove) aren't interested in sitting down and talking it over.
They have ideological reasons for doing what they are doing and have made it quite clear that they aren't interested in listening to education professionals about anything.
If it takes strike action to get the government to engage in the discussion you're talking about then so be it.