THIS month, I led a Westminster Hall debate about international parental child abduction.

Sitting in the gallery were ‘left behind’ parents, for whom time has taken on a different quality altogether, who measure their lives not in months or years but in missed birthdays, and the particular cruelty that comes with imagining how their children are growing up unable to see them. Understandably, for those watching proceedings, emotions ran high.

Reunite International puts the number of children taken from the UK by a parent each year at over 500. That figure alone should give us pause, and it almost certainly understates reality.

The legal architecture meant to address the removal of a child abroad comes in the form of the 1980 Hague Convention on the Civil Aspects of International Child Abduction. The world was rather different then. Nevertheless, it set out a clear principle: that a wrongfully removed child should be returned swiftly to their home country, and that proceedings should move expeditiously. Decades of practice have eroded both commitments. First, hearings are routinely delayed by months. Return orders granted at one level of a foreign court system are unpicked at the next, sometimes without any compelling new evidence or argument to justify the reversal. And the Convention's carefully drafted exceptions - provisions intended to protect children facing genuine, documented harm - have gradually expanded into something closer to a general-purpose escape clause. The original intent has been stretched almost beyond recognition.

After hearing testimony from families who have been failed by this system, a pattern emerges that is difficult to chalk up to incompetence alone. It is hard to shake the impression of conspiracy and collusion. There is a settled quality to the obstruction. Whether this reflects clear institutional bias or something else is a question the Polish authorities have conspicuously failed to answer.

Britain and Poland have a genuine friendship. They say that friends should be able to talk candidly with one another, even when it comes to uncomfortable discussions - in fact, especially when it comes to uncomfortable discussions. So, when the British Government says it raises these matters with Polish counterparts at every opportunity, I believe it. But opportunity and effect are not the same thing. What we want to understand is what kind of response these representations actually produce - because vague assurances, repeated often enough, begin to lose all credibility.

At home, the Crime and Policing Bill, which sailed through Parliament just before prorogation, will close a longstanding loophole and make all child abductions from the UK unlawful. It is a reform that should have come years ago, and its arrival is overdue.

But law reform at home cannot substitute for enforcement abroad. The parents I have met just want their children back. They want the orders of British courts to carry the weight they are supposed to. And they want a government prepared to say, clearly and persistently, that this matters, and to keep saying it until something changes.