Tony Blair has rejected a standards watchdog's call to curb the power of his top politically appointed aide to give orders to civil servants.
Jo Moore sparked a major row about special advisers
The Prime Minister's stance was branded as a "a seriously missed opportunity to enhance public
trust in the processes of government" by the Committee on Standards in Public Life, which recommended the change.
But the government says it will appoint an "ethics adviser" to help steer ministers away from conflicts of interest.
There is also a new code for special advisers, which follows the row over the infamous Jo Moore e-mail suggesting 11 September was a good day to bury bad news.
The moves are announced in the government's response to the committee's inquiry into the boundaries between ministers, special advisers and civil servants.
The government says it will produce a Civil Service Act, which would safeguard in law the impartiality of civil servants, but has given no commitment on when it will be introduced in Parliament.
The legislation will be drawn up once the Commons public administration committee publishes its recommendations on the issue.
The standards committee in April said special advisers should be stripped of powers to instruct civil servants - which were only introduced when Labour came to power in 1997.
Only Downing Street chief of staff Jonathan Powell and outgoing communications director Alastair Campbell have exercised those powers.
Number 10 has already announced that Mr Campbell's successor as media chief, David Hill, will not take the same powers.
But Mr Blair has rejected the call for him to give up the order in
council which in theory allows three special advisers in Number 10 to issue direct orders to civil
The prime minister said his government had accepted most of the committee's recommendations.
"A strong, effective, politically impartial civil service is a great national
asset," said Mr Blair.
"In general, the relationships between ministers, special advisers, permanent
civil servants, work extremely well.
"But we agree with the committee that a number of further sensible, practical
steps can be taken."
The new "ethics advisers" is aimed at giving ministers and top civil servants "an additional source of professional advice as required on the
handling of complex financial issues".
The government's new code for special advisers says
they should "not ask officials to do anything which is inconsistent with their
obligations under the Civil Service Code".
The code allows advisers to comment on advice officials prepare for ministers but not to "suppress or supplant that
Sir Nigel Wicks, chairman of the Standards' committee, said he doubted the government measures gave enough clarity to the boundaries between civil servants, special advisers and ministers.
"In short, we believe that the government's response represents a seriously
missed opportunity to enhance public trust in the processes of government," said Sir Nigel.
The committee also raised fears the civil service risked becoming politicised as the government seemed to want ministers to have the final say on appointing high-flyers from the private sector to senior civil service posts.
Conservative shadow deputy prime minister David Davis said the government's response was not enough.
"The reason such action is so urgently needed after decades of
successive governments managing to deal with the civil service appropriately is
this government's obsession with spin and record on corruption," said Mr Davis.
Liberal Democrat spokesman Paul Tyler said the growth in political appointments across Whitehall had undermined civil service independence.
"The prime minister's response to the report shows belated
recognition of this insidious deterioration, but no commitment to do anything
radical about it," said Mr Tyler.