How can an organization be impartial if the members of its board are appointed by the government and its funding is renegotiated every year?
We saw in 2003 what happens when the BBC disagrees with the government. The government wins. A minor mistake by a single reporter was excuse enough to get the entire BBC leadership fired for its criticism of the Iraq war.
Apparently impartiality means to shut up when the Prime Minister lies to parliament and to the nation.