What Happens When Proceedings Are Issued?
The issuing of proceedings is a "crystallising event". Where proceedings are issued between parties, they are entitled to raise any claim between themselves, within those proceedings, that existed at the issue date. However, there is nothing to prevent a party from waiting until their opponent's claim is out of time before they issue their claim. An example would be where a personal injury was sustained when a wall collapsed during construction. If the builder then waits 4 years before bringing a claim for unpaid invoices for the work, a defence cannot be raised based on the damage caused by the wall falling down.
Where a claim is brought against you and you believe someone else is also liable, you do not have to join them to the proceedings. However, if they are not made a party to the proceedings, you only have 2 years from the date of quantification of the original claim, to issue any claim against them.
If the person bringing that claim is a "protected party", then for limitation purposes time does not run whilst they are protected. They may be protected due to their age (under 18) or they lack the mental capacity to deal with the matter.