Cold water will not flow into machine

Only a small amount of water will flow through the cold water valve on the washing machine.
When I switched the hoses cold water will go through the hot water valve on the washing machine therefore it is not a problem with the hoses or the taps - it is something wrong with the ability of the water to get through the cold valve into the machine.
I have also checked the filters on the machine and they are clean and the hoses were not blocked.
A small amount of water does flow through into the machine via the cold valve, but just a very slow trickle and the hot valve is completely normal.
Any help would be rgeatly appreciated!