Analysis By Nick Assinder Political correspondent, BBC News website

Home Secretary Jacqui Smith's first job in the wake of the latest attempted bombings must be to reassure the public.

Ms Smith and Mr Brown have adopted careful tone

For a minister who had been in her job only hours before the attempted bombings occurred, she needs to show she has a firm grasp of the issues and a clear view of how to respond, and that she is up to the task of handling a crisis.

That is a pretty tall order for any minister in a new job, and it must be doubly difficult for one who has just stepped into one of the most notoriously difficult departments in Whitehall.

So, inevitably, all eyes are on Ms Smith as this crisis unfolds, to see if she can meet those expectations.

She certainly won plaudits from all sides in the Commons when she made her first statement in the job. Shadow home secretary David Davis praised both her and the prime minister for the calm and considered way they were handling the situation.

Ms Smith does, of course, now have the back-up of new ministers in the shape of former Metropolitan police chief Lord Stevens and former navy head Admiral Sir Alan West.

Ideological battle

But it is always tempting for a home secretary to simply get tough, and go to the Commons offering a version of "we told you so", before going on to demand ever-more draconian laws to deal with the threat.

Ms Smith is not rushing to legislation

Ms Smith's approach was entirely different, offering instead that calm, considered approach which is likely to maximise the cross-party support for any future changes she may propose.

Like the prime minister, she adopted a lower-volume reaction that is concentrating on seeking consensus over any new laws and focusing on the ideological battle - and, as far as the Commons is concerned, it appears to be working.

She echoed the prime minister's sentiment that this was not a time to rush legislation, but repeated the country would not be intimidated.

Coming on the heels of Mr Brown's recent remarks, it represents a distinct change of tone.

That is not to say that new laws, such as extending beyond 28 days the period of pre-charge detention, are not on the cards; they clearly are.

But it does suggest there might be some new thinking going on in government.

Another attack

At the moment, the response has met little criticism and there seems to be genuine cross-party agreement that the government is approaching this in the right way.

A successful bombing could change approach

Both the Conservatives and the Liberal Democrats have said they are happy to work with ministers to find the best way forward with any fresh legislation.

All this may change, of course, if there is another attack that succeeds.

There would then be headlines demanding immediate action, questions over the government's past actions and demands for full-scale investigations into events.

The cross-party approach would probably survive - as it did in the early days after July 2005 London bombings - but there could well be a change towards calls for all sorts of new laws.

That would provide another, even more serious test for Ms Smith and the Brown government.