By Jim Muir BBC Tehran correspondent

The pardon of a jailed reformist MP, Hossein Loghmanian, by Iran's Supreme Leader Ayatollah Ali Khamenei is the latest struggle between the country's conservatives and liberals.

Mehdi Karoubi, leading the walkout, forced the crisis' end

But it is hard to see who has come out of this latest confrontation with any real advantage or credit, apart from the Speaker of the Majlis, or parliament, itself, Mehdi Karroubi.

He won plaudits from many of his colleagues for bringing the crisis to a head, by walking out of parliament and essentially going on strike until the Supreme Leader intervened.

It is a tactical victory for the reformists, in that their jailed comrade has been released under the pressure they generated.

But many will feel it is a battle they should not have had to fight, and that a pardon from on high is not much of a triumph.

Time consuming

Instead of getting on with enacting reforms, they have been embroiled for weeks in a bruising dispute over the principle of parliamentary immunity, the latest of many crises to absorb and divert their energies.

Loghmanian was jailed for insulting the judiciary

And even that issue may still have mileage: two other reformist deputies face prison sentences on similar charges, and many more may also be on the list for later.

The principle of parliamentary immunity has been discredited by the powerful and highly conservative Council of Guardians, which vets and vetoes legislation passed by the elected Majlis - though the judiciary may now think twice about jailing an MP again, given the way it has been forced eventually to back down.

The affair has not enhanced the image of the Supreme Leader, Ayatollah Khamenei.

He was asked to intervene weeks earlier but declined, only to do so when he had virtually no choice.

As for the hard-liners, many will not be pleased Mr Loghmanian has been released.

But they have shown the power they can wield, and it surely will not be long before they show it again.

This constant wrangling and deadlock is watched with dismay by a public which voted heavily for the reformists, only to see them locked in disputes with the entrenched hard-liners and able to make very little progress.

No wonder some disillusioned deputies are advocating mass resignation and a referendum, while some other reformists are saying the path of moderation and dialogue has failed.

But those are minority voices. The struggle for reform will resume, with painfully slow results.