Along with the generous expenses claimed by MPs, another bone of contention has been the practice of many politicians to hold two, or even three, posts simultaneously.
The vast majority of Northern Ireland's MPs are also members of the Assembly.
As the largest party at both Westminster and Stormont, the DUP came under particular political scrutiny. Party leader and First Minister Peter Robinson and his wife Iris, who both hold dual mandates, have been branded the 'Swish Family Robinson' due to their enviable income.
Therefore his announcement earlier this year that the party would phase out dual mandates was widely welcomed and other parties were urged to follow suit. But it now appears that it will take up to six years before the double-jobbing by DUP MPs ceases.
Mr Robinson says it is not possible to stop the practice any quicker because that would mean divesting the Assembly of experienced politicians. The DUP, in common with most of the other parties, has a cadre of politicians long in the tooth and well used to the infighting of local politics, but is short on exciting new talent ready to step into the breach departing MPs would leave.
Nevertheless, Mr Robinson will find it difficult to shake off the jibe by opponents that he has backtracked on his previous promise to end double-jobbing. He may point out that MPs will not be able to claim their Assembly salaries after the next General Election, but they will still be entitled to the even more lucrative expenses of both Houses.
As the party with the greatest number of MPs, the DUP is most vulnerable to criticism on this issue. What it has done is create a breathing space for the other parties that face the same dilemma over double-jobbing. Their criticism of Mr Robinson's decision is more shadow boxing than hurtful punches.