While Downing Street is celebrating the negotiation of a new Northern Ireland agreement with the European Union, there is no evidence that this will improve Rishi Sunak's chances of overcoming the Labour Party's 400-seat lead in February's opinion polls. There is even the possibility that it will strengthen Labour's efforts to win the next general election.
There are no votes to be won in Great Britain by dealing with Northern Ireland. It is half a century since seats in Liverpool and Glasgow could be won by mobilizing votes along orange and green lines. Both the Conservative and Labour parties need to be within half a dozen seats of an absolute majority to be dependent on an Ulster party for a secure hold on Downing Street.
However, there are votes that the Conservatives can lose by their MPs splitting over whether to support the new agreement. The loss would have less to do with the content of the agreement than with the Conservatives appearing a divided government and Rishi Sunak a weak leader.
Photographs of Rishi Sunak and the President of the European Commission smiling at each other show that the agreement is a step toward repairing damage done to British-EU relations. However, they are a metaphorical red flag to Tory MPs who are implacably opposed to Brussels claiming any jurisdiction over any activities in any part of the United Kingdom, as is still the case.
The number of Tory MPs prepared to vote against the government is uncertain. That is why Downing Street is being cautious about what will be the phrasing of the motion that MPs are asked to endorse when the agreement is put to the House of Commons at some unspecified date. There is little the whips can say to encourage hard-line Brexit MPs to back the government if they have already accepted that Labour will take their seats at the next election.
The size of the split will depend not only on what is in the agreement but also on what is in the mind of Boris Johnson. The former prime minister has already made it known that he fears Sunak is backsliding on Brexit. Moreover, he has maintained the belief among a substantial number of MPs that he is invariably a vote-winner. However, a repeat of Johnson's appeal to get Brexit done in the next Parliament would be an admission of the Conservative government's failure to get it done successfully in the current Parliament.
The Labour Party gains from Conservative divisions by appearing as a united party as, by contrast with Tory MPs, it will be united in backing Sunak's agreement with Brussels. The split in the Scottish National Party over the choice of its new leader has shown the electoral damage that disunity can do. Whereas in January the SNP was forecast to win 47 seats at the next general election, February polls indicate that Labour will benefit from the SNP split as the forecast number of SNP MPs in the next Parliament is down by almost one-sixth.
Richard Rose is Britain's senior psephologist and an expert on party government. His new book 'How Sick is British Democracy?: a Clinical Analysis' is published by Palgrave.