Pete Bunting, Assistant General secretary of the Irish Congress of Trade Unions and I had a fun time giving evidence before the Northern Ireland Affairs Committee this afternoon. I’d better apologise to Peter publicly though as I did, I think, get more than ,my fair share of the time.

As was said by the Chair soon after we started, the message that I was not a fan of tax rate unity had been heard loud and clear.

I made these points:

1. The legal precedent for a separate tax rate for NI precludes it applying to finance companies and those supplying intra-group services. That destroys most of the market for inward investment in NI.

2. Almost all the arrangements for ring fencing against transfer pricing abuse suggested by the likes of PWC, the CBI and KPMG will fall foul of the EU Code of Conduct (and yes, it will apply).

3. The profits attracted will not stay in NI — it will be a conduit. And that’s exactly what those promoting this idea — who say they want to create a “profit centre” in NI intend.

4. If the effective rate of corporation tax in the UK is now at least 7% less than the headline rate the real rate in NI under this arrangement might be little more than 5% — meaning that the tax loss will be well over £300 million a year. This loss will have to be made good by the local people of NI, who if the arrangement creates a conduit will see few or no extra jobs as a result.

5, Having a low CT rate in NI will create all the distortions in the economy we saw when we had a 1`0% tax rate in the UK as a whole — which was a complete and outright mistake. And this loss will again have to be paid by most people in NI.

6. 12.5% has been a good calling card for the Republic but the truth is their real rate is near enough 0% and if NI seeks to copy that it will fall foul of large parts of UK law and outright transfer pricing disputes will break out between GB and NI — who will need different tax authorities to deal with this.

7. Managing transfer pricing across the NI — GB border will be a massive impediment to locating business in NI.

8. Hong Kong is not a model for NI — and following the Durkin model would be madness because NI is not a conduit for physical goods to anywhere — but HK is.

9. At best going down this route would create massive uncertainty for a long time to come about the legality of the tax regime in NI at considerable cost to its people but because of the uncertainty it will not deliver for business and so will, fail as a policy.

10. Delivery6 of a policy of demand stimulation in NI and GB would be much more beneficial.

11. Giving bank guarantees and mezzanine finance to local businesses who want to grow will be much more effective as a use of funds.

We covered much more, but that’s a flavour.

And the exchange was a lot of fun — as it seems they agreed too.

If it puts a stake through this ill-informed policy so much the better too.