The Government has insisted it is not planning to “rewrite” the Civil Service code, after suggestions that such a move was being considered as part of the Rwanda plan sparked a backlash from trade unions.

Downing Street insisted on Wednesday that it is not seeking to “rewrite” the formal set of principles for civil servants and instead wants to provide “clarity” for ministers and officials over the application of the Rwanda Bill.

It comes after illegal migration minister Michael Tomlinson said the Government was considering tweaking the code to address the concerns of right-wing Tory MPs that the legislation does not do enough to block last-minute injunctions from the European Court of Human Rights.

The comments prompted criticism from trade unions representing civil servants, as well as questions about the feasibility of such a move.

Number 10 said on Wednesday that it is not “seeking to rewrite the Civil Service Code”.

The Prime Minister’s official spokesman said: “What we are looking to do is to provide further guidance so there is clarity for ministers and civil servants on the application of this.

“This is simply about ensuring that civil servants act within the code.

“This is simply about making sure that we’ve taken every conceivable step to ensure that we get flights off the ground as quickly as possible should the Bill progress through the House, as we continue to believe it will.”

The proposal emerged after former home secretary Dame Priti Patel on Tuesday urged Rishi Sunak to ensure “all potential roadblocks are removed, including the Civil Service blob”.

The senior Tory said the Prime Minister should make clear that the “Civil Service code cannot be used by officials to obstruct decisions”.

Unions had reacted angrily to the comments by Mr Tomlinson, who had told BBC Radio 4’s Today programme “there will be further confirmation that it will be for ministers to decide and then, once those decisions are made, they will be carried out” by civil servants.

Dave Penman, general secretary of the FDA union which represents senior civil servants, said amending the code would amount to ministers obliging officials to breach the law and would put civil servants in an “invidious position”.

“The ministerial code says you should not put civil servants in a position where there’s a conflict between their obligations under the Civil Service code and instructions you give them as a minister.

“Pretending that you can do that is not actually doing it because a civil servant has to deal with facts, not illusion or bluster or rhetoric,” he told PA news agency on Wednesday.

Garry Graham, deputy general secretary of the Prospect union, also labelled any move to change the code a “desperate attempt by the party of government to placate their own backbenchers”.

Human rights lawyer Adam Wagner said any such plans would be “obviously a non-starter”.

“Civil servants can only advise on the basis of the law, and the Government’s advice from the Attorney General and (barrister) Sir James Eadie apparently is, rightly, that Rule 39 measures must be complied with in order not to breach the UK’s duties under the European Court of Human Rights.

“So it’s not civil servants who make these decisions, and amending the Civil Service code won’t make any difference,” he said in a post on social media.