Martin McGuinness's description of Northern Ireland First Minister Peter Robinson's threat to resign as "grandstanding" hits the nail on the head.

Robinson's latest tantrum follows his earlier "look at me" moment when he worked himself into a lather over the issue of royal insignia on Prison Service emblems.

And instead of pointing out to his fellow unionists in December 2012 that there was nothing to be gained by demanding that the union flag be flown more frequently from public buildings in Northern Ireland than in Britain, he gave credence to the street protests and disorder that this demand provoked.

Robinson and his supporters constantly attempt to blackmail Westminster over these pretexts, claiming that failure to deal with them could present a crisis in the peace process.

In reality, crisis is their goal because only through creating a siege mentality among their supporters can they justify their existence and anachronistic positions.

The crisis to which they react is within unionism, whereby Robinson's Democratic Unionist Party (DUP), the Ulster Unionist Party (UUP) led by Mike Nesbitt and assorted splinters compete to harness the most recalcitrant supporters of Orange supremacy.

The DUP leader asserts his ignorance about Northern Ireland Office letters issued to so-called on-the-runs (OTR), assuring them that they were no longer at risk of prosecution.

Former UUP first minister David Trimble is equally insistent that he knew "absolutely nothing" of the letters and accuses the British government of conspiring with Sinn Fein.

"I don't know anybody who knew about it," he declared for emphasis, which suggests that he ought to get out and about a little more often.

Deputy First Minister McGuinness and North Belfast MLA Gerry Kelly, who was a Sinn Fein negotiator, are adamant that both major unionist parties were fully in the loop over OTR.

"He knew about the OTR situation, he knew they were crucial to the peace process and the political process," said Kelly.

Former Progressive Unionist Party chairman and peace process negotiator Plum Smith also casts doubt on unionist bigwigs' "I know nothing" position, acknowledging that courageous late secretary of state Mo Mowlam gave verbal assurances to republicans and loyalists about non-prosecution for pre-1998 offences.

Smith says that his party, which represented the Ulster Volunteer Force paramilitary group, was asked to supply its own OTR list to be treated the same as republicans.

"For the DUP to say they didn't know is nonsense," he insists.

Tory frontbenchers accept that they cannot change a policy brought in by the Tony Blair government and continued by their own conservative coalition.

However, they are quite content to play to the gallery by underlining how angry, sickened and so on they are about murderers running free and by stressing their concern for such people's victims.

The grief still experienced by the families of those killed at Hyde Park or Enniskillen is undeniable and the same goes for hundreds if not thousands of Irish civilians killed by Crown forces, but this slaughter has been covered up or excused for decades.

The whole idea of the Good Friday Agreement was to put an end to further suffering for any family and to encourage politicians to rise above historical sectarianism by working together for the common good.

Robinson should bear this in mind and make it his priority rather than mobilising sentiments of resentment and alienation with the object of delivering votes in May's district council elections.