Gordon Brown is due to appear before the Iraq Inquiry on Friday 5th March.
Sir John Chilcot has a duty to ask Gordon Brown about the criminal offences under UK law that he carried out in relation to the Iraq War.
Regime change using force (boasted of by Blair on 29th January 2010) has been "an act of terrorism" in UK law since 1993 (see Section 2(2) of the Reinsurance (Acts of Terrorism) Act 1993).
It remained an act of terrorism as defined in Section 1 of the Terrorism Act 2000.
Funding terrorism is an offence under Section 15 of the Terrorism Act 2000. The penalty, on conviction, is 14 years imprisonment.
Gordon Brown funded the Iraq War by virtue of his role as Chancellor of the Exchequer during the relevant periods.
Chilcot has a duty to ask Brown about that funding of an invasion and regime change by force that was an "act of terrorism" in UK Law.