Cameron pressures Gaddafi to step down

[Feuer Frei!]

I don't think any amount of pressure or wherever it comes from will force him or persuade him to step down.
He was already quoted as saying recently: " "I will fight to the last drop of my blood."
And if you are thinking sanctions will, the sanctions' effect(s) would be limited. Freezing Gadhafi's accounts, enforcing a weapons embargo and not granting visas to his officials will not deter him from continuing his war against his civilians. If in countries like Iran and Sudan the sanctions were meant to encourage people to change their government or show the regimes they risked losing popular support, in Libya the popular revolt already happened, without the sanctions. And the leader couldn't care less about legitimacy in the eyes of the people. It seems the sanctions are used more to express solidarity with the Libyan people than to stop the war or penalize Gadhafi.