On a public roadway residents have no proprietary rights to the kerbside immediately outside their properties, except to the right of access and egress.
If encroachment takes place to the extent that access is impossible, the matter should be reported to the council’s Parking Enforcement Officer.  It is important that the officer can see the incident for himself.
if the encroachment is partial and access can still be achieved, it is suggested that full details should be taken and that a polite notice be placed on the offending vehicle, if this does not have the desired effect, then contact the Parking Enforcement Officer.
A resident may try to assert parking rights by placing cones to prevent others parking. Whilst this may prove to be effective for a period, it would appear to be indefensible if challenged.