Home Secretary John Reid says he has yet to see any evidence to support the introduction of phone-tap evidence in court cases.
Phone tap evidence is presently not admissible in court
He is due to publish his review of anti-terror legislation before Christmas, possibly including new laws.
While he said he was "not yet persuaded" about allowing phone-tap evidence, he stressed that his review was incomplete.
There was no suggestion in the Queen's Speech of new powers for phone-taps.
"I have not yet concluded nor have I yet received the results of a study we are carrying into whether we could use it while minimising the damage to our [operations]...and that is very important - the operations of MI5, MI6 and our intelligence services," Mr Reid told ITV's Sunday Edition.
Phone tap evidence generated in the UK cannot be used in British courts at present.
There has been strong resistance to the idea from the British intelligence services, on the basis that scrutiny in courts of this evidence might reveal operational details.
Mr Reid also said he would consider extending the time-limit under which terror suspects can be held without charge to 90 days only if police presented enough evidence to support it.
Last week, the prime minister said he remained in favour of a longer detention period, as asked for by police, but wanted to proceed by consensus.
The government's plans to bring in a 90-day limit on detentions were voted down by the Commons last year, with MPs and peers eventually settling on 28 days. Previously, the limit had been 14 days.
Lord Carlile, the government-appointed expert who oversees terrorism laws, has said he expected new anti-terror measures, possibly including 90-day detention, to be published early next year.