LONDON (Reuters) -British security forces may have thwarted two further attacks since suicide bombers hit London”s transport system in July and killed 52 people, British Prime Minister Tony Blair said.

Blair, who has been forced to shelve counter-terrorism plans to avoid losing his first major vote in parliament, accused critics of his tough proposals of &#34woeful complacency.&#34

He insists that police need powers to hold terrorism suspects for up to 90 days compared to the current limit of 14.

But on Wednesday rebels in Blair”s ruling Labour party cut his parliamentary majority to just one — its lowest ever — over his counter-terrorism measures.

To avoid outright defeat over the 90-day detention measure, Home Secretary (Interior Minister) Charles Clarke withdrew and promised a new round of cross-party consultation.

Blair, returning to the attack after a bruising week when close political ally David Blunkett also resigned, told the Sunday Telegraph: &#34I still think there is a woeful complacency about a lot of the public debate about this.&#34

&#34The police told me, and the security services back them up, that they may have stopped two further attempts since July 7,&#34 Blair said. &#34There are people we are tracking the whole time.&#34

On July 7, Islamist militants killed 52 people with a string of coordinated suicide bomb attacks on three London underground railway trains and a bus.

Blair said: &#34I find it really odd that we”re having to make the case that this is an issue when virtually every week somewhere in the world terrorists loosely linked with the same movement are killing scores of people.&#34

If he fails to get the measures through, then Blair said he would &#34feel a sense of defeat not so much for me as it were — although obviously that”s true — but for the security of the country.&#34

Police chiefs say cases nowadays can be so complex and overlap so many borders that they desperately need more time to question suspects.

London”s Assistant Police Commissioner Andy Hayman, a leading figure in Britain”s anti-terrorism strategy, said: &#34The networks we are dealing with are now global in terms of their operations.&#34

&#34Many terrorism suspects now use stolen documents or identities, sometimes dozens from many different countries,&#34 he told the News of the World, stressing the need to stretch the power to detain to 90 days.

He said after the July 7 attacks, it took two months to search a waste site where the bombers had dumped material. Police had to comb through the equivalent of eight Olympic-size swimming pools.