A spokesperson for the department insisted there were ‘no agreed timelines in place' to announce the clusters despite sources claiming they had been due to go live on Monday.
Under the plans, the current 42 ICBs will be merged into around 27 clusters.
According to sources close to the new structures, questions remain unanswered over how redundancy payments – expected to be in the region of £200m – will be funded.
The DHSC spokesperson said: ‘ICBs will be crucial as we deliver our shift out of hospital and into the community as part of our 10-Year Health Plan.
‘Clustering will allow ICBs to harness a shared budget of sufficient size to improve efficiency and reduce running costs.'