Labour has taken a changeable stance on GDS since it was set up in 2011. Onwurah describes the unit's work as "absolutely critical" and says it has done a "fantastic" job of attracting top tech talent into the public sector.
However she says "we're still not in a position to say what form GDS would or should take under a Labour government".
Onwurah has previously been critical of GDS, claiming it has alienated Whitehall departments and other parts of the public sector.
Her fellow shadow minister Lucy Powell recently slated Cabinet Office minister Francis Maude for failing to deliver the promised 25 redesigned digital exemplar services by last month's deadline.
Despite these criticisms, Onwurah supports widening GDS' work to the local sector - not through top-down schemes, but by setting up "local digital factories" to build and share software among councils.
A series of regional bodies might be the best option given "local authorities themselves are too small and central government too remote", Onwurah suggests.
She won't be drawn into providing further details, saying "we're still discussing what that might mean in practice".
But she says: "It's not about a local GDS based out of Whitehall. I don't think that would work. You need something rooted in communities but with support from central government.
"Council leaders say they want access to better skills and shared services, as there are huge cost pressures on them. But they don't want to be told how to meet the needs of the people that have elected their authority. I think technology can square that circle because it can be local but still have standard interfaces."
Onwurah is clear is on the official target for SMEs to get 25 percent of Whitehall spending: Labour would scrap it.
She says the party does not want to have a specific percentage target for SME spending.
"They are always liable to be gamed, as has been done", Onwurah says, referring to the government's doubtable claim it is now spending 26 percent with SMEs, announced in February.
However Labour "wholeheartedly" supports the focus on encouraging more SMEs to bid for government work.
"I think SMEs bring innovation and they also support the local economy - there are lots of reasons why you want SMEs in there," Onwurah says.
She says the party is keen to push further to do away with barriers to SMEs winning public sector businesses, for example by examining which frameworks help and which hinder SMEs.
"We're looking very closely at the digital services framework and G-Cloud," Onwurah adds.
Government as a Platform
Onwurah sounds genuinely enthusiastic about 'Government as a Platform': moving to common, shared technology platforms across government, with public services built on a shared core. GDS has promised it will work to make this aim a reality after the election.
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