All a bit desperate trying to paint Labour as hypocrits.
While the Conservative Party’s largest donor, who has given the party £millions, has evoided huge amouts of tax, the best the Mail can come up with is:
// Mr McDonnell receives a Westminster Council pension which comes from a fund managed by a Guernsey-based firm. //
McDonnell has no say over who Conservative Westminster Council appoint to run their pension fund. And McDonnell never worked for Westminster Council, so it might be some legacy from the GLC.
Yep really desperate reporting.