Deputy Prime Minister Nick Clegg will reveal the progress made in his constitutional reform ambitions when he addresses Parliament on Monday, he told the Hay festival.

Speaking at the event in Mid Wales, Mr Clegg said he would detail some of the early developments in his “menu” to change the political system.

He told the audience: “I will be making some announcements tomorrow in the House of Commons about some early progress on the big building blocks in the constitutional reform agenda which is extraordinarily ambitious.

“Reforming the House of Lords has been talked about for one hundred years and we are absolutely determined to do something about it this time.

“Looking at boundaries, looking at the electoral system through a referendum, regulating lobbying, looking at party funding. This is a huge, huge menu.

“Have I worked out exactly how you sequence it? No. But I will be making some announcements tomorrow.”

Mr Clegg also told the audience there must be “a presumption of disclosure” with regards to the Chilcot Inquiry and its openness would be the key to determining its legitimacy.

He said: “The battle that needs to be fought is to make sure in the final Chilcot report the presumption is towards real, meaningful, thorough disclosure.

“The acid test for the Chilcot Inquiry for its legitimacy and cathartic value, for a country still trying to grapple to come to terms in the way that we did, is it needs to be fully open.

“I know for a fact they have sought to have access to far more documents that they thought and the challenge is to make sure there is real disclosure when they publish their findings.

“There needs to be a presumption of disclosure.”

When asked if this was a view shared by his Tory colleagues, Mr Clegg said “I’m sure everybody agrees. This is not a game between politicians.

“What is really important is Chilcot does what it was supposed to do, which is make sure everyone understands how the decision was reached so that we can learn lessons and make sure we never again have a government hell-bent on going to war and able to bamboozle Parliament and the British people.

“That must never happen again.”

The Liberal Democrat leader also addressed the situation in Israel, saying Europe must wield its economic power to command more influence in the Middle East.

He said: “Europe has always been an economic giant in the region, it is by far the biggest donor of aid and technical assistance to the Palestinian communities, it is also by far the biggest market for the export of Israeli good and services, but it has always acted as a political pygmy.

“One of the things we are going to seek to do, I’ve spoken to David Cameron and William Hague about this and we all agree, is to mobilise Europe’s economic might in the region to act with greater influence and balance alongside the United States in the Middle East.”

He added he believed negotiations between Israel and EU would remain frozen until Israel’s blockade of Gaza is lifted.

He said: “The new agreement has basically been put on ice and I think it will remain on ice until this blockade is lifted and there is a clearer strategy of where next.

“I am the staunchest defender of Israel’s right to defend itself and secure the safety of its own citizens but my question to my Israeli friends is what is the strategy?

“I genuinely feel lifting the blockade is one very important step in securing Israel’s security interests.”

He stressed he was referring only to the new agreement between Israel and the EU, adding: “I’m not talking about unpicking previous agreements.”

He added: “I think if you look at our reaction over the last week people have been quite struck by how forceful and quick how united we have all been in saying very bluntly every day, the blockade of Gaza is wrong, it is a humanitarian catastrophe.

“It is a heartfelt assertion on the part of us all that is, on humanitarian grounds, that you have a million and half people on a slither of land the size of the Isle of Wight with a very young population and humanitarian supplies not coming in the way it should, with an economy on its knees, a seething environment in which frustration, anger and radicalism is only likely to grow.

“It has to end.”