A process for the preparation of homo or copolymers of ethylene, said process comprising: i) in a first polymerisation stage, continuously polymerising ethylene and optionally at least one C3-10 α-olefin, the reaction mixture further comprising a diluent and a metallocene catalyst having at least one optionally substituted indenyl ligand, said first polymerisation stage being effected essentially in the absence of hydrogen and with an ethylene concentration of 0.005 to 25 % mol relative to said diluent, preferably 0.005 to 4 % mol to a yield a polymer slurry; ii) in a second polymerisation stage continuously polymerising the polymer slurry resulting from said first polymerisation stage with the addition of further ethylene and optionally at least one C3-10 α-olefin and optionally hydrogen; wherein the first and second polymerisation stages are so effected that the ratio of the weight of polymer produced in the first polymerisation stage to the weight of polymer produced in the second polymerisation stage is 0.1:99.9 to 20:80, that the polymer produced in the first polymerisation stage has long chain branches and that essentially no further long chain branches are formed during the second polymerisation stage.