Thursday marks a climax of the Greek debt crisis with private creditors having to respond to an offer that would see them write off more than 70 percent of the face value of their bonds in return for new debt with a series of promises.

With Greek government bonds currently trading at less than 20 cents in the euro and the risk of a total wipeout if Greece decided to unilaterally refuse all payments, a majority will likely go for it. Legally-binding majorities are another matter.

One danger is that the prospect of countries opting for such a swap may scare creditors in larger countries like Italy and Spain where currently no bond haircut is expected by the market, thanks in large part to the ECB's liquidity injections.

And the upshot for many economists is that there will be a longer-term price to pay for governments for tinkering with the rules of the game, as many investors view it, via the likes of retroactive bond legislation and obfuscation of CDS markets.

Although Berlin, Paris and Brussels insist the Greek case is a one-off and European Central Bank liquidity has insulated the wider banking system, Portugal's 10-year bonds still trade as low as 50 cents in the euro and many creditors reckon it will be very difficult for the country to avoid some restructuring.

Economist Shayne Heffernan said today that when Government Bonds are trading at a 50% plus dicount, clearly that is a troubled economy.

Even the 10-year debt of fellow bailout recipient Ireland, which many investors reckon has the underlying economic capacity to go back to the markets next year, is still trading at less than 90 cents in the euro and many doubt its imminent market return.

Athens said this week it aims to force 90 percent acceptance but if the takeup is at least 75 percent then it would consider triggering so-called collective action clauses retroactively inserted into the bonds issued under Greek law, about 85 percent of the 200 billion euros being restructured.

Those clauses in practice force all affected creditors to comply.

But it's this distinction between debt issued under domestic laws and that sold under internationally-accepted English law that some say has consequences for other troubled euro nations eyeing Greece's so-called Private Sector Involvement, or PSI.

Shayne Heffernan

Shayne Heffernan oversees the management of funds for institutions and high net worth individuals.

Shayne Heffernan holds a Ph.D. in Economics and brings with him over 25 years of trading experience in Asia and hands on experience in Venture Capital, he has been involved in several start ups that have seen market capitalization over $500m and 1 that reach a peak market cap of $15b. He has managed and overseen start ups in Mining, Shipping, Technology and Financial Services.