Do I have to pay estate agent?

[ohhello]

House went on market 14 weeks ago (sole agent 12 weeks contract with ea) offer straight away and been waiting all this time for chain to get sorted. My new build are getting impatient now and may offer a part exchange. Do I still Have to pay my ea fees if I sell it to the new build company?

You would have to terminate the contract with the EA first and check the terms.
I seem to recall when we sold our flat that if we sold within a certain number of weeks after ceasing contract that we would still be liable for fees.

You'd have to consider whether it's worth paying in order to complete the sale. Alternatively tell EA you're thinking of pulling out and see if they can speed up the process.