Process for the preparation of a high molecular weight branched polyamide polymer, comprising a melt-mixing step wherein - an essentially linear polyamide (pre)polymer (X-1), predominantly consisting of AA-BB repeat units, - an essentially linear polyamide (pre)polymer (X-2), predominantly consisting of AB repeat units, and - a branching agent, are provided to and mixed and heated in a melt mixing apparatus, thereby forming a mixed melt, and the mixed melt being cooled, thereby forming a solid mixture; and a solid state post condensation step wherein the solid mixture is post-condensed at elevated temperature in the solid state, thereby forming a high molecular weight branched polyamide polymer. wherein - the (pre)polymers (X-1) and (X-2) are provided in a weight ratio (X-1)/(X-2) in the range of 0.25 - 4; - the (pre)polymer (X-1) and/or the (pre)polymer (X-2) have a viscosity number, measured according to ISO 307, in the range of 50 - 250 mL/g; - the branching agent is a branched polyamide oligomer/prepolymer comprising a branching unit derivable from a monomer (referred to as monomer C) having at least three functional groups being either amino groups and/or carboxylic acid functional groups or precursor groups thereof, and optionally AA-BB and/or AB repeat units; - the branching unit is present in an amount in the range of 0.05 - 1 mole%, relative to the total molar amount of AA repeat units, BB repeat units, AB repeat units and branching units; - the high molecular weight branched polyamide polymer obtained after the solid state post condensation has a relative viscosity measured according to ISO 307 of at least 2.5. a melt-mixing step wherein - an essentially linear polyamide (pre)polymer (X-1), predominantly consisting of AA-BB repeat units, - an essentially linear polyamide (pre)polymer (X-2), predominantly consisting of AB repeat units, and - a branching agent, are provided to and mixed and heated in a melt mixing apparatus, thereby forming a mixed melt, and the mixed melt being cooled, thereby forming a solid mixture; and - an essentially linear polyamide (pre)polymer (X-1), predominantly consisting of AA-BB repeat units, - an essentially linear polyamide (pre)polymer (X-2), predominantly consisting of AB repeat units, and - a branching agent, a solid state post condensation step wherein the solid mixture is post-condensed at elevated temperature in the solid state, thereby forming a high molecular weight branched polyamide polymer. wherein - the (pre)polymers (X-1) and (X-2) are provided in a weight ratio (X-1)/(X-2) in the range of 0.25 - 4; - the (pre)polymer (X-1) and/or the (pre)polymer (X-2) have a viscosity number, measured according to ISO 307, in the range of 50 - 250 mL/g; - the branching agent is a branched polyamide oligomer/prepolymer comprising a branching unit derivable from a monomer (referred to as monomer C) having at least three functional groups being either amino groups and/or carboxylic acid functional groups or precursor groups thereof, and optionally AA-BB and/or AB repeat units; - the branching unit is present in an amount in the range of 0.05 - 1 mole%, relative to the total molar amount of AA repeat units, BB repeat units, AB repeat units and branching units; - the high molecular weight branched polyamide polymer obtained after the solid state post condensation has a relative viscosity measured according to ISO 307 of at least 2.5. - the (pre)polymers (X-1) and (X-2) are provided in a weight ratio (X-1)/(X-2) in the range of 0.25 - 4; - the (pre)polymer (X-1) and/or the (pre)polymer (X-2) have a viscosity number, measured according to ISO 307, in the range of 50 - 250 mL/g; - the branching agent is a branched polyamide oligomer/prepolymer comprising a branching unit derivable from a monomer (referred to as monomer C) having at least three functional groups being either amino groups and/or carboxylic acid functional groups or precursor groups thereof, and optionally AA-BB and/or AB repeat units; - the branching unit is present in an amount in the range of 0.05 - 1 mole%, relative to the total molar amount of AA repeat units, BB repeat units, AB repeat units and branching units; - the high molecular weight branched polyamide polymer obtained after the solid state post condensation has a relative viscosity measured according to ISO 307 of at least 2.5.