Is the "opt out" trade union political levy any different to the PPI mis-selling scandal?

Above:  the main editorial in today's Guardian addressed the issue of party political funding.

The more I think about the trade union political levy the more convinced I am that it cannot stand up to scrutiny.

Is the "opt out" trade union political levy any different to the PPI mis-selling scandal?  Big companies and corporations try this "pre-ticked" scam every so often, and almost always have to abandon it in the face of legal review or consumer watchdog condemnation.  How can the trade unions get away with this?

Presumably the levy is intended to "buy" for each member political representation from the Labour Party?  If the levy is not voluntary but has been "pre-ticked" by the trade union then surely it is illegal and the Office of Fair Trading needs to intervene?  Surely the Labour Party realises that money gained through such a technique is not worth having?

Instead of going down the "pre-ticked" route why don't they simply sign up Labour Party members at the same time as they enrol people into the trade unions?  They will have access to the trade union membership lists.  Selling Labour Party memberships is no different from any other subscription sales campaign - all they have to do is demonstrate the features and benefits of Labour Party membership in a way that convinces people to buy.

I also want to see the Tory Party convert itself into a mass-membership organisation.

Political institutions are too important to be funded by vested interests.

There is no place for big money in politics - it corrupts everyone and corrupts everything.