my 03 megane wont start even when u push it?

my o3 plate renault megane wont start theres no warnings on the dash board it just tells me to remove the fob key.so i try again but i get the same clicking noise as before.but when i opened the bonnet i could hear a buzzing noise at the top of the engine somewhere in the middle.sometimes i can push it and jump start it but it wont let me do that anymore could you please give me a clue what it might be.