Cameron has signaled in advance that the government is willing apparently to concede ground on purdah - the period where taxpayer's money cannot be used by the government to publicly campaign in a referendum:
David Cameron is backing down on his refusal to impose a period of “purdah” in the runup to the EU referendum in a concession to his Eurosceptic backbenchers.One of the reasons is Cameron is no longer pursuing purdah so vigorously is he has changed his strategy. Instead of going for "Article 48" reform, mainly because the EU has told him no, he's adopting the Associate Membership option available in a future EU treaty - a treaty which can only happen after the UK's referendum. Purdah, or its removal, thus becomes less important to him.
In addition he has the use of statutory instruments. After the Referendum Bill has passed, statutory instruments can be used to amend the Act at a later date to "water down" purdah restrictions under the radar of media coverage. He may seem to give in now but statutory instruments allows the government to achieve its aims with less media attention at a later date.
In effect it would be the use of salami tactics to nullify purdah and it would be a tactic taken straight out the EU guide book, which they call engrangé (gearing). Engrangé is where Monnet initiated the drip-by-drip process of integration by pushing a series of harmonising regulations to bring the economic activities of the member states closer together. So regulation is not the consequence of the process of integration - it is the means by which it is achieved.
In other words "engrangé, engrangé, engrangé, onwards" (with apologies to Tennyson). Monnet would be proud of Cameron...