As the PPC has alleged that the driver has breached the contractual terms entered into by the conduct of parking and remaining at the location, we have to examine whether that is actually a fact.
For a "contract" to be valid has to have three elements. 1. An offer. 2. Acceptance of the offer and 3. "consideration".
Here is the sign they have provided evidence of that is supposed to be the contract agreed to by the driver:

The sign does not explain how to obtain a permit, therefore it lacks the clarity required for a valid offer. The sign attempts to form a contract between the driver and PCM UK. Here’s how:
Offer: The sign outlines the terms and conditions under which parking is allowed, such as displaying a valid permit and parking within a marked bay. It specifies a key term: "By entering or remaining on this land you agree to abide by all of the Terms & Conditions." This language is the offer for parking under certain conditions.
Acceptance: By parking there, the driver accepts these terms through conduct. This is the way in which contracts are formed in private parking cases—by entering the car park and parking, the driver is deemed to have accepted the terms displayed on the sign, whether they bother to read it or not.
Consideration: The sign sets out a parking charge of £100 for any breach of the stated conditions (such as not displaying a permit or parking outside marked bays). The 'consideration' for the driver is the ability to park on the land and the 'consideration' for PCM UK is the right to issue a charge (PCN) if the driver breaches the conditions.
However, for the contract to be enforceable, a few factors must also be considered:
Clarity: The terms on the sign may appear clear, but the size of the text and prominence of the key terms (such as the parking charge) need to be visible and legible to the driver.
Prominence: If the sign is not easily visible or if key terms are obscured, a driver might argue that they were not given a fair chance to understand the offer before accepting by conduct.
This sign does attempt to form a contract, and the driver who parks in breach of the conditions could be liable to pay the parking charge, subject to compliance with the parking regulations and any law. However, the clarity, visibility, and legibility of the sign could be relevant in determining the enforceability of the charge should it be disputed in court.
However... the fact that the sign does not explain how the driver can obtain a valid permit is a point that could undermine the formation of a valid contract.
Lack of Essential Information: For a contract to be valid, it must provide the essential terms clearly. In this case, the requirement to display a valid permit is a key term, but the sign fails to explain how the driver can obtain such a permit. Without this information, the driver is not given a fair opportunity to comply with the contract's conditions.
Uncertainty: A contract must have clear terms that both parties can understand and agree to. If the driver does not know how to obtain a permit, the terms regarding the permit are ambiguous. A court could find that PCM UK have failed to make the terms clear enough for the driver to understand their obligations and therefore no contract was formed.
Fairness and Reasonableness: Under the Consumer Rights Act 2015, terms in consumer contracts must be fair and transparent. If the driver has no reasonable way of knowing how to comply with the permit requirement, a charge for failing to display a permit could be deemed unfair, making the term unenforceable.
The omission of instructions on how to obtain a permit weakens PCM UK's case for enforcing a parking charge. If a driver challenges the charge, this would be a strong defence.