Hopefully you have found some similar threads. Your defence is yours, but you could make some of your points using wording along these lines as a framework:
(1) The Defendant denies that the Claimant is entitled to relief in the sum claimed, or at all.
(2) It is admitted that the Defendant was the registered keeper of the vehicle at all material times, but liability is denied.
(3) It is denied that a contract was entered into with the Claimant by conduct. To form a contract, there must be an offer, acceptance, and valuable consideration. The signage the Claimant relies on is entirely prohibitive, containing no legitimate offer to park on certain terms. Accordingly, it is denied that any contract was formed between the driver and the Claimant.
(4) Even if a contract was formed (which is denied), it is submitted that the alleged contractual terms relied on, namely a blanket prohibition on stopping, including stops borne out of necessity/safety, are impossible to safely comply with and therefore cannot give rise to liability due to being unfair under the Consumer Rights Act (2015).
(5) As the Claimant does not know the identity of the driver of the vehicle in question, the liability of the defendant must be considered in his capacity as the registered keeper of the vehicle. It cannot be assumed that the keeper was also the driver (VCS Limited v Ian Mark Edward (2023) [H0KF6C9C]).
(6) The land in question is covered by the Leeds Bradford Airport Byelaws (2022) and as such is not relevant land as defined in paragraph 3, Schedule 4 of Protection of Freedoms Act (2012). Accordingly, the Claimant is unable to recover any charges from the Defendant in his capacity as the registered keeper, under the provisions of Schedule 4 of Protection of Freedoms Act (2012).
(7) Whilst liability for the entire claim is denied, the Defendant further denies liability for the additional costs of £70, vaguely referred to by the claimant as "contractual costs", above and beyond the £100 parking charge. The added costs are an attempt at double recovery of capped legal fees (already listed in the claim) and are not monies genuinely owed to, or incurred by, the Claimant.
An example of something you may wish to add, is a point between (3) and (4),
briefly outlining what actually happened (e.g. the vehicle stopped out of necessity).
