Hotpoint few12p fills halfway up the drum then stops. Two lights begin to flash meaning the machine cannot fill. Have replaced the water pressure switch but problem remains.

SOURCE: Hotpoint Aquarius WD420 5+5Kg

The water level vacuum switch are not working , check hose might lose.

SOURCE: WMA61 Hotpoint Washing Machine 'Red Tap' symbol is flashing

well if your sure the other end is connected to the tub and is tight then id replace the switch its out of calibration it works off positive pressure from the water in the tub if you can blow in it and it actuates doesn't mean its working off the right pressure from the tub

SOURCE: Washing machine wont stop filling up

check hose to water level switch, if it has had an out of balance situation it can loosen or detach hose. replace hose firmly back on switch or replace hose if that doesn't work.

SOURCE: Filling With Water

Set the water level selector to a lower level. The sensor will always work if the water level is much higher than the trigger level. However, the "much higher" condition is never reached if the water is about to overflow.

SOURCE: Hotpoint Washing Machine Model # VBXR1060T4WB Filling Problem

problem could be the pressure stat which is a switch which detects water level or the pipe leading up to this switch or the air chamber the pipe goes to.
take top off. locate the pressure switch - has a small diameter pipe going to it. remove pipe and fit a similiar one. put on fill and pressurise this pipe by mouth and water fill should stop. if it doesn't, then switch is faulty.
if this is ok, examine carefully the small diameter pipe for splits and blockage. also check the air chamber for build up of gunge