The stunning way in which Finance Minister Dwight Duncan has injected his personal opinion into the debate about the London Stock Exchange (LSE)/TMX Group merger is shocking.

What is he thinking, tossing the deal into the political arena?

The deal may now be doomed, but by turning it into a political football, Duncan ensured that rather than having a rational discussion, we’ll get a partisan round of overblown rhetoric from a bunch of partisan hacks.

In a testy scrum with reporters on Tuesday, Duncan questioned whether the deal is a merger or a takeover.

“I think they should quit calling it a merger. It’s not,” he said.

“If it’s an investment, great. If it’s a takeover and moving it to London, that’s not what we’re interested in.”

Duncan announced all-party committee hearings on the merger, led by veteran MPP Gerry Phillips. The Ontario Securities Commission will also review the deal.

Meanwhile, Industry Minister Tony Clement has also announced a federal review of the deal.

Whether or not the deal goes through, the response — and particularly Duncan’s strident denunciation of it — are worrying and add fuel to the perception around the world that Canada is increasingly protectionist and does not seek to do business with the outside world.

Who’ll seek to do business with Canadian companies after this?

One of the early sticking points for Duncan seemed to be that the largest shareholder in the deal was Sheikh Mohammed bin Rashid Al Maktoum of Dubai.

How ironic!

Just a few weeks ago, provincial trade and economic development minister Sandra Pupatello was in Dubai — only this time she was slamming Prime Minister Stephen Harper for not extending landing rights for the United Arab Emirates’ two airlines.

The feds had good reason to do that. The airlines, Emirates and Etihad, are rapidly expanding and would swallow up the Mideast and Asian routes of Air Canada and its partners in the Star Alliance.

Look, there’s no doubt the TMX/LSE deal raised serious questions — especially in the mining sector.

Big companies like Xstrata and Vale weren’t greatly affected. Vale isn’t even listed on the TSX, just Rio and New York.

But smaller companies and exploration outfits were jittery. Some feared the cost of dealing with EEC’s bureaucratic regulations. Others find the TSX more flexible when it comes to raising funds for exploration.

Between 1999 to 2009, the TSX and venture exchange (TSXV) handled 80% of mine financings in the world and 36% of total equity capital raised globally in the mining sector. In 2009 alone, they accounted for 84% of world mine financings and 34% of total equity raised.

There’s massive expansion going on in mining in this province — not just in the so-called Ring of Fire, but also in diamond and gold mining.

According to the TSX website, as of Dec. 31, 2010, 1,531 mining companies are listed in Toronto — more than any other stock exchange. In 2010, there were more new mining listings — 208 — in Toronto than on any other exchange.

So the stakes are high, if you’ll pardon the pun.

All the same, let’s not forget this was a deal of willing partners. And it’s always better to deal with a partner — rather than a predator. And that’s what could happen if this deal fails.

Meanwhile, the province should be careful about meddling.

It brags about its “Open Ontario” policy — then slams the door shut on people it doesn’t like.

christina.blizzard@sunmedia.ca Twitter: @ChrizBlizz