Government IT contracts still favour large incumbent suppliers, according to SMBs that have filed complaints varying from not getting paid to struggling to renew their deals.

The claims come in the latest Cabinet Office status report on its Mystery Shopper Service, launched in 2011 to help suppliers overcome poor procurement practices.

The report reveals that the service had to deal with more than 270 cases from September 2012 to February 2014, with 53% of complaints levelled against the procurement process itself.

While that is a reduction on 2013’s 81% of complaints coming against the process, it also led to a rise in complaints in other areas.

The report said the service is still aware of issues where suppliers complain that frameworks favour larger contractors.

It recommended: "Our advice is to allow sufficient time for the market to respond to mini-competitions and to be careful not to encourage uneconomic bids which can waste the time of smaller suppliers."

A recent Institute for Government report revealed that the ‘Big Six’ IT suppliers netted a combined £4.3bn through Government IT contracts last year – though the figure is disputed.

It also blamed a rising tide of complaints over contract renewal opportunities on poor communication.

It said: "We have seen an increasing number of complaints from suppliers who are holders of existing contracts, but who are not being given the chance to bid for new ones. It seems some incumbents are not being made aware that contracts will be changing in size or structure and are not told when, how or where they will be advertised."

It called on public sector buyers to talk to existing suppliers as the end of the contract approaches.

"Our advice therefore is to talk to incumbents. This does not mean giving them an unfair advantage, but just making sure that as the end of their contract approaches, suppliers know what is happening," it read.

The Government is not keen on automatic contract renewals as it seeks to up SMB spends to 25% of all IT expenditure by 2015.

But the report also said many suppliers are either not being paid on time or at all, while "the majority of [contract management] issues falling below the first tier were payment issues."

A total 64% of contract management issues regarded payment.

More than two-thirds of all complaints over the period, or 70%, came from the wider public sector, with central Government accounting for 24%.

The report said: "Within these wider public sector issues, the biggest concern remains the procurement process."