Fuel pump

A fuel pump for use in a common rail fuel system for an internal combustion engine comprises a plurality of pump assemblies (12), each of which has a pumping plunger (14) which is reciprocable within a respective plunger bore under the influence of an associated drive arrangement (20, 22, 24) to perform a pumping cycle during which fuel within a respective pumping chamber (18) is pressurised to a relatively high level. The drive arrangement for each pump assembly is arranged to impart reciprocating movement to the associated pumping plunger (14) upon co-operation with a cam surface. At least one of the pumping plunger (14) and the plunger bore is provided with a collection groove (50) which is registerable with a return passage (52) during at least a period of the pumping cycle, the return passage (52) being provided with a venturi device (54) in communication with a low pressure drain (58) such that, in use, leakage fuel within the collection groove (50) is permitted to flow to the low pressure drain through the venturi device (54).