Gone is the rose-tinted vision of Israel as an island of democracy in a sea of irrational and violent Arabs. Gone is the belief that Israel wants to negotiate, if only it could find a partner to talk to. Gone, too, is the notion that there is symmetry in this conflict, that this is a battle between equals.

This is not the effect of a larger Muslim community in the UK. All Britons today are more likely to be aware of the 14,000 settlements Israel approved during its nine-month peace talks with the Palestinians; to wonder where a Palestinian state is going to go, with more than 600,000 settlers in occupied East Jerusalem and the West Bank; to acknowledge the insouciant racism of Israeli discourse about all non-Jews; to recoil at the cost in Palestinian civilian lives of Israel's definition of its own security.

The more Israel insists its supporters choose between their liberalism and their zionism, the weaker its case becomes that the two can co-exist. Britons are losing faith that a solution is just around the corner. The idea of Israel is changing in the minds of its allies. It is no longer a cause. It is becoming heavy baggage.

Monday's vote in the UK parliament on whether to recognise Palestine as a state, therefore, does not come out of the blue. Neither did the largest-ever demonstrations seen in Britain on this conflict during the recent Gaza war. Nor did the resignation of  Foreign Office minister Lady Warsi, the highest-placed British politician yet to resign over the UK's "morally indefensible" stance over Gaza. Warsi was no George Galloway, a figure on the political fringe. She remains a mainstream politician who was actively courted by the two other major political parties on her resignation.

Therefore her plea in the Observer on Sunday to recognise the state of Palestine carries political as well as moral force: "There is a lack of political will and our moral compass is missing," the former Foreign Office minister told the Observer. "There are no negotiations, there is no show in town. Somehow we have to breathe new life into these negotiations, and one of the ways we can do that is by recognising the state of Palestine."

The vote will be a symbolic one. A Palestinian state is a virtual concept, and it has already been recognised by 134 states, most recently by Sweden. But there is nothing symbolic or theoretical about the pressure applied by the Israel lobby on MPs of all parties to toe the line, but particularly on a Labour Party led by Ed Miliband. The vote in favour would amount to an historic act of defiance with an ally used to dictating the terms of the debate.

Israel and America's argument that recognition and the reluctant, faltering moves by Palestinian President Mahmoud Abbas to join United Nations institutions such as International Criminal Court would prejudice the outcome of meaningful talks is holed below the water-line. There are no meaningful talks.

What greater prejudice to the outcome of a negotiated solution could there be than the monthly announcements of settlements, which, unlike moves in the UN, take immediate and concrete shape and for which Israel pays no cost? Who does more to de-legitimise the state of the Israel than the state of Israel itself? As former UK foreign secretary William Hague himself said, how long can this go on without the two-state solution dying? It is by all appearances already dead and it will take not much before the coroner issues its death certificate.

Warsi revealed the support she got for her position from the "highest levels" of the Foreign Office after her resignation. She accurately described the vice-like grip on policy of  a "small group of politicians … who are not allowing public opinion, ministerial views, parliamentary views and the views of the people who work in this system".

This is not a debate about outcomes, a one- or a two-state solution. It is about the ability of Israel to fashion and limit the international debate; to ensure that it takes place only within carefully defined parameters; to insist that it continues to enjoy  impunity for its actions; to lessen the pressure on it to come to the table.

Occupation, as Abbas has himself said, is cost free to the occupiers. The strategy by all members of the international community has now got to be to start making it more  expensive. The debate and the vote will be an important start.