only have available to it by way of defence

Вот полный контекст:

If such an Indemnified Person brings proceedings to enforce the terms of sections 1.5 each such Indemnified Person shall only have available to it by way of defence, set-off or counterclaim a matter that would have been available by way of defence, set-off or counterclaim if that Indemnified Person had been a party to this Application Form. Such an Indemnified Person may not assign or transfer a right to enforce a term of this Application Form under the Third Parties Act;