In Poland "Phoney war" is treated as betrayal by UK and France, who only declared war against Germany and did not perform any other actions. This combined with Soviet attack on 17th September is said to be one of main reasons of lost of the war.
However, in my opinion, it is not 100% fair to say UK did not do anything. The Royal Navy began fightings at the very beginning and one can believe it was everything they could do. Sources say France launched Saar Offensive and "Britain and France also began a naval blockade of Germany on 3 September which aimed to damage the country's economy and war effort." (source). However, I can't find what this blockade look on the French side. All I can imagine was (like in WW1) that UK was responsible for North Atlantic (including North Sea) while France -- for Mediterranean (which has little sense as Italy was neutral then and there was no other enemy country like Austria-Hungary or Turkey during WW1).
What major or even minor actions did France performed during late 1939?