It relates to a status achieved called "Persistent Evader". A vehicle must have 3 or more outstanding PCNs against it, after all recovery options have been met. That includes going through the bailiffs where their Warrants run for 12 months for each PCN.
This is not something that can be done instantly just because 3 or more PCN have been issued against a vehicle.
It's buried within the Traffic Management Act 2004 and in reality isn't that new on balance.
Quote from Operational Guidance
to Local Authorities:
Parking Policy and Enforcement
Traffic Management Act 2004:
Persistent evaders
8.105 Some vehicle owners contravene parking regulations deliberately
and often, and fail to settle the debts they incur. A vehicle owner
can be classed as a ‘persistent evader’ if there are three or more
recorded contraventions for the vehicle and the PCNs for these
have not been paid, represented against or appealed against within
the statutory time limits, or their representations and appeals
have been rejected but they have still not paid. Usually this is
because the vehicle keeper is not registered, or is not correctly
registered, on the DVLA database and the owner is confident that
they can avoid paying any penalty charges. An authority should not treat
a vehicle owner as a persistent evader unless bailiffs have failed to recoup
the outstanding and unchallenged penalty charges. Where a vehicle appears
to be registered in the UK, but the identity and address is not registered,
or is not correctly registered on the DVLA database,
authorities should consider making the information available to the
police who can, if appropriate, investigate any criminal offence.
8.106 When parked in contravention, a persistent evader’s vehicle should
be subject to the strongest possible enforcement following the issue
of the PCN and confirmation of persistent evader status. This is
likely to involve immobilisation or removal. The benefit of removal
is that it requires proof of ownership and a registered address
before release of the vehicle, whereas immobilisation prevents law
abiding motorists from using valuable kerb space. If a vehicle of
a persistent evader is in a designated parking place, the Traffic
Management Act 2004 and regulations made under it prohibit an
enforcement authority from immobilisation or removing the vehicle
until at least 15 minutes81 have elapsed following the issue of a
PCN. Currently, under TMA regulations an authority can only obtain
payment for the PCN of the contravention for which the vehicle
is immobilised or removed and not any other outstanding PCNs.
8.107 London Councils has set up a persistent evader database and all English
authorities may use it. Alternatively, authorities may wish to maintain a
database themselves, or in conjunction with neighbouring authorities.