Opponents of Sinn Fein constantly harp on about the party's murky past, desperate to warn people against being taken in by the shiny, new, all-inclusive face of Irish republicanism. It's a wonder that they bother at all when Sinn Fein itself is so adept at providing regular, unpleasant reminders of its dark underbelly.

Take last week's decision by Sinn Fein councillors on Drogheda Borough Council to vote against the awarding of the freedom of the town to Seamus Mallon. Mallon was the inaugural Deputy First Minister of Northern Ireland. He's a former Irish Senator. A former civil rights activist. A former Member of Parliament for Newry and South Armagh for nearly 20 years. From 1979 to 2001 he was deputy leader of the SDLP. He was one of the principal architects of the peace process.

The principles of consent and co-operation which were enshrined in the Belfast Agreement were those by which the 81-year-old has always lived his life, both politically and personally.

A statement read out on behalf of the mayor at last week's meeting of the town council summed up Mallon's legacy perfectly: "I believe that he is a patriot in the true sense of the word and has worked to unite Protestant, Catholic and dissenter like a true republican."

In fact he's a patriot in the only sense of the word that matters, because any definition of national identity that needs to draw its strength from undermining or attacking someone else's is just another brand of toxic ethnicity.

As it happens, Sinn Fein didn't have the numbers on Drogheda Borough Council to stop the honour being awarded to Mallon.

It doesn't even have the numbers to form a five-a-side football team. He will be formally given the honour next month.

But the deeper question remains: if republicans cannot even show respect to such a giant of modern constitutional Irish nationalism as Seamus Mallon, what chance is there that they will ever show respect to unionists?

Sinn Fein is making a big deal right now of seeking accommodation with people on the other side of that ancient sectarian divide.

The party's new young MP for West Tyrone Orfhlaith Begley promised after her recent by-election win to "reach out with an open hand in friendship to our unionist neighbours".

Last year the party's Stormont leader (whatever that meaningless title now means) Michelle O'Neill also vowed to "reach out the hand of friendship to unionists". It's almost as if they're all reading from the same book of platitudes.

As for new leader, Dubliner Mary Lou McDonald, she waxed lyrical in these pages last month about the wondrous united Ireland that she wanted to see come into being. It would, she promised, be "an Ireland in which you can comfortably be Irish, or British, or both, or neither". It was an Ireland that could "be home for my family and for Arlene Foster and her family".

But not one, apparently, in which Seamus Mallon can be given due honour for a lifelong commitment to the peaceful resolution of political differences without republicans spitefully trying to sour the occasion.

Sinn Fein's problem is that it always wants to put off the day of reconciliation. Respect for other cultures and traditions is always postponed to some magical date in the future, never now. In the meantime it just wants to indulge in a spot of tribal triumphalism one more time.

The party could, for example, have extended the hand of friendship to unionists by calling off the online army of trolls who mustered to force a hotel in Co Donegal to cancel a planned afternoon tea over the weekend to coincide with the wedding of Prince Harry and Meghan Markle.

It would have been a harmless day out for anyone who wanted to watch the wedding in company. Instead, what were described as "angry republicans" (are there any other kind?) decided that their Irishness might be fatally threatened by the sight of people who don't see the world exactly as they do daring to have a good time.

So, they bullied local businesses out of generating a bit of much-needed income from an event that was being enjoyed internationally for the good-humoured spectacle that it was and which won't come around again on the same scale for at a least few more decades, until George, Charlotte and Louis get their turn.

Mary Lou did manage to squeeze out a few anodyne words to wish the royal couple well on the day, but where were all the self-proclaimed peaceniks in Sinn Fein when hotels were being intimidated, or when RTE was being criticised for showing the wedding live on Irish TV?

They were nowhere to be seen, just as they all scarpered when their colleagues in Drogheda were doing their best to prevent Seamus Mallon getting due recognition for his part in building peace not just when it suited him - like former members of the Provisional IRA, who now pretend to be Mahatma Gandhi - but every day of his political life.

Sinn Fein councillors in Co Louth say they voted against giving the Markethill man the freedom of Drogheda on the grounds that it was "wrong to elevate only one person involved in the peace process", but they must think we were born yesterday to fall for such far-fetched excuses. Republicans never object when it's one of their own being honoured.

When New York mayor Bill de Blasio officially renamed this year's St Patrick's Day as 'Gerry Adams Day', with Taoiseach Leo Varadkar in attendance, offering sycophantic applause, there were no protests from republicans that other politicians were being excluded from the honour.

When Martin McGuinness was nominated for the Tipperary Peace Award in 2016, Sinn Fein representatives did not demand that his name be removed from the shortlist and replaced with a collective commendation for all those involved in the peace process.

But when it's Seamus Mallon, suddenly the rules of the game change and honours for him must be opposed.

It would be tempting to say that Sinn Fein will never move on until it ends this blatant hypocrisy, but what's worrying is that it doesn't seem to do the party any harm with a certain section of voters.

An opinion poll published at the weekend south of the border saw Sinn Fein overtaking Fianna Fail to become the second most-popular party in the country.

Too many younger voters will simply never know the moral strength that it took for men like Seamus Mallon to keep their heads while republicans, who despised him, were losing theirs and too many older voters have, shamefully, forgotten.

Belfast Telegraph