Taking things on trust

By Mark Devenport BBC Northern Ireland political editor

If Tennyson is right that "there's more faith in honest doubt" than in half the creeds, should observers be forgiven for retaining a degree of scepticism about the allegations flying around regarding the Northern Bank robbery, the IRA and money laundering?

More than £26m was stolen from the Northern Bank

No link has yet been proven beyond reasonable doubt and no convictions have yet been secured.

However, the British and Irish governments, their police chiefs and the Independent Monitoring Commission remain adamant that their intelligence is correct.

On that basis, the government has decided to impose fresh financial sanctions on Sinn Fein.

Washington-based priest Fr Sean McManus, who heads the lobby group the Irish National Caucus, has accused Bertie Ahern of making "incendiary and irresponsible" charges without due process.

Liberal Democrat spokesman Lembit Opik did not go so far.

But in the Commons this week, he asked Northern Ireland Secretary Paul Murphy to share any evidence with his party leader Charles Kennedy on a confidential, or privy council, basis.

Lembit Opik asked Paul Murphy to share evidence in secret

Mr Murphy said he would consider the request. However, no-one had yet been in touch with Mr Kennedy's office several days later.

Even if the government widened the circle of those "in the know" and gave secret briefings to Westminster opposition politicians, it would not enlighten the general public.

Such briefings would not prevent Sinn Fein politicians from denouncing the allegations as "baseless" and telling their supporters that the latest sanctions are merely the latest attempt by direct rule ministers to enforce their will on nationalist voters.

The money laundering searches in Cork, Dublin and elsewhere temporarily halted this line of counter attack.

However, the failure of that investigation - as yet - to reach a definitive conclusion linking the IRA to the Northern Bank robbery means the argument has resumed where it left off.

Some intelligence sources, such as informers within the IRA's ranks, will never be revealed by London or Dublin.

But should other kinds, such as the transcripts of wire taps or other surveillance material, be kept under wraps when the stakes are so high?

Sinn Fein said it found this bugging device in its headquarters

The admissibility of wire tap evidence is a topic of hot debate elsewhere in the UK, mainly in relation to the battle against al-Qaeda.

Some senior police officers, such as new Metropolitan Police Commissioner Sir Ian Blair, have supported the use of wire tap evidence in the courts.

Other security figures, like former MI5 Director General Sir Stephen Lander, argue that by opening wire taps up to proper examination in the courts, the authorities will "expose what we can and what we cannot do".

But does anyone believe Irish republicans have not cottoned on to the notion that someone in some network information unit might be listening to their calls?

Martin McGuinness's telephone conversations with Mo Mowlam and Jonathan Powell have appeared in print, whilst anyone covering last year's Leeds Castle talks will remember Gerry Adams and his team returning to the government a bug the size of a large plank.

Yet when I questioned Paul Murphy about wire tap evidence a couple of weeks ago, he was non-committal.

MI5 will take charge of intelligence gathering in Northern Ireland from 2007, a decision primarily aimed at curtailing the transfer of sensitive powers to local politicians.

But the move hardly inspires confidence that intelligence material will be made any more open, either to the courts or to the public.

Until then, the ping pong games of accusation and denial look set to continue, leaving the voters to make their minds up on the basis of hints and hunches rather than the whole truth.