16/06/2013 19:56 BST | Updated 16/08/2013 06:12 BST

The G8 Summit - A Great Moment for Britain, A Great Test for the Prime Minister

Hosting the G8 Summit is a great moment for Britain, as well as a huge test for the Prime Minister.

The location alone - set in a peaceful and prosperous Northern Ireland - is testament to what can be achieved through politics and dialogue and a credit to the work of politicians in delivering real change.

All the issues on the agenda at this week's summit deserve urgent and coordinated action by the G8, but they also provide an opportunity to shine a light on the important contribution the UK can, and should make, to the international community.

First, the pressing priority for the G8 must be to reach agreement on bringing the brutal conflict in Syria to an end. Announcements from Washington regarding the evidence about the use of chemical weapons show just how grave the dangers confronting Syria are.

Already into its third year, the United Nations now estimates that over 93,000 people have lost their lives in this horrific and violent conflict.

At the summit the Prime Minister should be fully committed to the task of enlisting the support of the Russians in bringing all sides of the Syrian conflict to the negotiating table. The G8 provides a rare window of opportunity for intense and coordinated diplomatic efforts to secure agreement with the Russians and it is only right that David Cameron, as chair, drive this agenda.

But the G8 leaders gather this weekend with a shared obligation to address the suffering of Syrian refuges in the region. Whilst the tragic scale of the humanitarian crisis in Syria grows, the appeals for funding from the United Nations are still shamefully underfunded. The UN appeal is still almost 30% underfunded, leaving a gap startling gap of $3.8bn that is still desperately needed.

This cannot be allowed to continue and this week, all the G8 leaders present must agree to meet their respective commitments to fund the humanitarian appeal for Syria. We hope and believe that the Prime Minister should set delivering upon this as a clear test for the summit.

Second, the summit must reach agreement on putting the G8's own house in order on tax transparency.

The UK government has failed time and time again to show the leadership needed by refusing to review tax rules, which are estimated to cost developing countries over £4bn per year in lost tax revenues.

This isn't good enough, and the Prime Minister should use the window of opportunity presented by the G8 summit to deliver real action to tackle tax avoidance. While the some progress was made at the Open for Growth event this weekend, we need more than just secretive lists of who owns companies in the UK and vague promises of future transparency in tax havens. The enormous amount of public pressure put on the government by NGOs, faith groups and people of all political persuasions is testament to how resonant these issues are to the British people.

Labour has also called on the government to introduce proposals for country-by-country reporting and a fundamental reform of the rules which allow multinational companies to shift their profits and avoid tax. The government should be doing more to ensure developing countries benefit from greater transparency.

The last time the UK hosted the G8, Labour brokered ambitious agreements on tackling poverty in Africa and tackling climate change, through a combination of political will and public engagement.

Sadly this scale of commitment has been largely lacking from the Prime Minister's approach this time around. Instead of building alliances, he has risked our international standing just when our influence matters most.

This summit offers the Prime Minister a chance to show Britain at its best, and the test for its success will be reaching agreement on some of the most challenging issues facing the international community. We hope he seizes that opportunity with both hands.