William Hague, Harriet Harman and Bob Marshall-Andrews discuss the Tzipi Livni question at PMQs yesterday.

On Tuesday, I blogged about the diplomatic row triggered by a British court issuing an arrest warrant for the former Israeli foreign minister Tzipi Livni. It rages on.

At PMQs yesterday (watch the video above), Bob Marshall-Andrews asked Harriet Harman whether she would support the power of the courts to issue proceedings against anyone where there is sufficient evidence. It was a clear reference to this case. Harman replied that she supports judicial independence.

But the plot thickens. The present law allows the courts to issue a warrant for a non-citizen who has allegedly committed a war crime in another country. Today it has been reported that this will change, with Gordon Brown said to be pushing for plans to build in "safeguards" in criminal cases against visiting foreign leaders. These "safeguards" will entail granting the attorney general full power of veto for suspected war criminals.

It might just be me, but does that sound like an encroachment on judicial independence?

It was also reported that Brown telephoned Livni to tell her that he "strongly opposed" the warrant, while the Foreign Secretary, David Miliband, called Livni and his Israeli counterpart, Avigdor Lieberman, to apologise. A diplomatic nicety, perhaps, but the planned changes to the law -- which follow calls from Israeli politicians to, well, change the law -- signal a much more worrying collision of politics and justice.