why was de gaulle anti-british?

I give you some good reasons: French and British were Allied. That however did not prevent Churchill to shoot into pieces the French fleet anchored at Mers El Kebir, deliberately murdering 1309 French sailors. In retaliation the French (Vichy) Air Force bombed Gibraltar and French colonial troops were so eager to shoot on "Tommys" that the US Army had to carry out the North African invasion. De Gaulle had hoped to draw those North African troops onto his side without fighting them, but Churchill simply had crossed out those plans. At latest since Mers El Khebir and the shooting of the commander of the French submarine "Surcouf" in the harbor of Portsmouth by a British Navy's prize command France was at war with Great Britain. Not to speak about the British Expedition Force's unfriendly act of deliberately detonating all major French port facilties on their flight from the German Wehrmacht, letting their French friends fight alone on the continent, leaving behind the exploded port facilities of Dunkirk, Cherbourg, Le Havre and many others, which ironically were later rebuild by the occupier. Churchill and Roosevelt wanted to turn France into some puppet state under Anglo/American tutelage like Germany. De Gaulle did his best to prevent it. Having in fact prevented it was probably one of his greatest achievements. Those who do not know "Mers El Kebir" are those being confused why the French do not love their former allied unconditionally.

Because he resented the fact that Britain was the saviour of his nation and could never get over the fact that the Royal Navy was obliged to sink the French fleet in harbour in order to avoid it falling into German hands. Churchill was not anti-French although in 1940 he made the comment that Britain would be more effective without the millstone of having to defend the French around its neck. Churchill was in fact a great European although he would have been dismayed at the current European Union - he imagined a Europe lead by Britain and not one in which the most puny of European nations could hold the UK to ransome.

I didn't think Churchill was anti-French. He suggested a joint union between the UK and France in the dark days of 1940.