New Delhi, July 29 - Prime Minister Manmohan Singh Wednesday asserted there was no dilution in India's stand on cross-border terrorism but argued there was no alternative to engagement with neighbours.

'We can have a meaningful dialogue with Pakistan only if they fulfil their commitments in letter and spirit not to allow their territory to be used for terrorist attacks against India,' Manmohan Singh told parliament in his response to the debate on the July 16 India-Pakistan joint statement issued after a meeting with his Pakistani counterpart Yousuf Raza Gilani in Sharm-el-Sheikh.

His reasoned reply came after the opposition as well as supporting parties came down hard on the prime minister, accusing him of compromising India's consensual stand of not having a dialogue with Pakistan till that country ends cross-border terror.

'There is no dilution of our stand in this regard,' Manmohan Singh assured the house even while warning Pakistan that any Mumbai-like attack will put an 'intolerable strain' on the bilateral relationship that he was seeking so hard to maintain.

Allaying apprehensions about the 'delinking of action on terror from the composite dialogue' - a controversial formulation in the joint statement that has been decried by critics - Manmohan Singh said Pakistan knows very well that action on terror is 'an absolute and compelling imperative that does not depend on the resumption of dialogue'.

Manmohan Singh said Pakistan 'must show the same political will and resolve against terrorists on its eastern border as they seem to have done so against terrorists on its western border'.

The prime minister shared with parliament the details of the steps taken by Pakistan against the Mumbai attackers in the form of a 34-page dossier given to India July 11 -- which appeared to have prompted him to start limited engagement at the level of foreign secretaries.