At statute law (24A Police and Criminal Evidence Act 1984):
24A Arrest without warrant: other persons
(1) A person other than a constable may arrest without a warrant—
(a) anyone who is in the act of committing an indictable offence;
(b) anyone whom he has reasonable grounds for suspecting to be
committing an indictable offence.
(2) Where an indictable offence has been committed, a person other than
a constable may arrest without a warrant—
(a) anyone who is guilty of the offence;
(b) anyone whom he has reasonable grounds for suspecting to be guilty
(3) But the power of summary arrest conferred by subsection (1) or (2)
is exercisable only if—
(a) the person making the arrest has reasonable grounds for believing
that for any of the reasons mentioned in subsection (4) it is
necessary to arrest the person in question; and
(b) it appears to the person making the arrest that it is not
reasonably practicable for a constable to make it instead.
(4) The reasons are to prevent the person in question—
(a) causing physical injury to himself or any other person;
(b) suffering physical injury;
(c) causing loss of or damage to property; or
(d) making off before a constable can assume responsibility for him.
[F2(5) This section does not apply in relation to an offence under Part
3 or 3A of the Public Order Act 1986.]] (stirring up racial or religious hatred)
Are the security guards committing an indictable offence? If they are committing assault occasioning actual bodily harm, or worse than that, then yes. Less than that, then likely no.
You can be reasonably confident they will call the police and wait for the police to attend. Therefore you don't need to make the arrest yourself, you can ask the police when they arrive. So this situation doesn't seem to satisfy a condition of the statute, unless you are suffering physical injury (but is that because of the guards behaviour or your resistance).
Someone attempting to escape citizen's arrest commits the offence of escape from lawful custody and someone using force to resist or escape commits the offence of assault with intent to resist arrest. But I imagine it unlikely that there would be a prosecution in the circumstances described.
At common law any person has the power to arrest for a common law breach of the peace, which is far more broad.
Practically speaking the security guards are unlikely to stop restraining you just because you use some magic words. Generally it seems best for you to comply at the time (reducing the risk of injury to all involved) and (if you have a case against them) complain and sue later. If you try to use force you may well put yourself at legal risk (criminal or civil).