Politicians and their families appear to be trying to pilfer as much as they can, an elected representative told an inquiry into House of Commons expenses today.

Northern Ireland Assembly member Dawn Purvis warned the team the public's confidence in its representatives had "haemorrhaged" because of nepotism.

The Committee on Standards in Public Life is considering banning MPs from employing family members as assistants or researchers.

Ms Purvis told the Belfast meeting: "Maintaining the current degree of nepotism in our political practices creates another layer of exclusion, protects political dynasties, and creates the appearance of politicians and their families trying to pilfer as much as they can."

Committee chairman Sir Christopher Kelly is holding hearings before recommending changes to expenses and allowance rules at Westminster later this year.

Ms Purvis said the party was recommending the end of unregulated hiring of family members, which is currently practised as "nepotism without justification".

"In some situations it may be that a family member is the most appropriately qualified person to perform a function in a member's office and in such a case it should be allowed," the Progressive Unionist Party (PUP) leader said.

"However, the very appearance of nepotism is damaging to the institution and therefore must be openly explained and justified."

She has been working on a private members' bill to end dual mandates between the Assembly and local councils.

Some MPs in Great Britain work up to 70 hours a week in London but in Northern Ireland they are able to combine their positions with roles as ministers and MLAs and in some cases councils.

Mr Robinson, SDLP leader Mark Durkan and Sinn Fein deputy First Minister Martin McGuinness are among those splitting their time between the Assembly and Westminster.

The DUP is among those proposing reform of the system. Sinn Fein Assembly member Alex Maskey gave evidence to the Committee today.

He wanted to see an end to dual mandates but believed the devolved institutions were too "unstable" to proceed at present.

"There are many actually within the mainstream unionist parties who have not yet committed themselves to participating fully in the government on the basis of equality and real partnership," he alleged.

Committee chairman Sir Christopher said even if the individuals changed there would still be five Sinn Fein MPs. He asked Mr Maskey how many times Sinn Fein MPs had flown to London but he was unable to provide details.

Mr Maskey defended Sinn Fein's abstention from Westminster seats, based on opposition to British rule and a refusal to swear an oath to the Queen, and said party members were regularly in London for work.

Ulster Unionist deputy leader Danny Kennedy said he wanted to see an end to payments to abstentionist MPs.

"To say that a person is in some way half pregnant, you are either pregnant or not pregnant," he added.

Witness and Belfast Telegraph journalist David Gordon, who has written extensively on the matter, called for greater transparency and said there should be more details about flights to London taken by Northern Ireland MPs.

"It doesn't help politics in general if it is dominated by these individuals or I would say highly subsidised by public money."

SDLP Assembly member Alban Maginness said there were plans to publish Stormont expenses by November.

"We believe that the present situation arose because a flexible and potentially abusable expenses system was allowed to evolve as an alternative to a robust and equitable salary arrangement.

"It is necessary to ensure simplification to the current expenses process."