A dispute erupted after the Conservative Party published what it claims to be the cost of a five-year Labor government.
The report, written by the party and not by the Treasury, is based on a number of commitments made at the Labor Party's annual conference, but not on its manifesto.
Chancellor Sajid Javid said Labor's proposals would leave the UK "on the brink of bankruptcy".
But Chancellor in the Shadow, John McDonnell, called the report "false news".
Conservatives say Labor Party policy would cost £ 1.2 billion over the next five years if the party wins next month's general election.
The figure is based on the cost of Labor's 2017 Manifesto and other commitments made since then.
But the Labor Party still has to publish its 2019 election manifesto detailing its policies and spending proposals.
Senior Labor Party officials will meet next weekend to decide what policies adopted by the party's annual conference will become manifesto proposals for the government, and some will have little chance of making the cut.
What is the accuracy of the claims?
The Conservative Party's approach is problematic.
As the Labor Party has not yet published its election platform, previous commitments may well be canceled, while new ones may be added.
This makes it impossible to accurately quantify the election promises at this stage of the campaign.
Although some political positions were adopted at the Labor Party conference, there is no guarantee that they will be adopted in the next manifesto.
There is also a problem with some of the costs. For example, the Conservatives cost the union's plans to renationalize 196 billion pounds. This is based on an estimate by the Confederation of British Industries, which has itself been criticized.
But it is certainly true that the Labor Party wants to spend a lot more, which it was frank.
Chancellor John McDonnell said he was more than doubling investment spending in the UK to reach an additional £ 55 billion a year.
The Institute for Fiscal Studies has questioned the potential for such an immediate increase in investment spending.
- More information about Reality Check on the union's economic projects here.
Mr McDonnell called the Conservative report "ridiculous ridiculous" and "misguided misadventures of distorted estimates and miscalculations, concocted because they know that the movement's plans for real change are popular".
He added: "The Conservatives will be able to know everything about these plans – and their actual cost – when we publish our fully encrypted manifesto."
The Conservative document comes after the head of the public service, Sir Mark Sedwill, blocked a Conservative plan to use officials to cost Labor's budget plans in a separate report.
Sir Mark's decision was made after Mr. McDonnell complained to Permanent Secretary of the Treasury Tom Scholar.
"A political document"
This document is political rather than financial. The goal of the Conservatives is to frame the Labor Party's plans not so ambitious, but also unaffordable.
But the record assumes that all Labor policies are firm commitments and it does not review Labor's income generation measures.
John McDonnell did not hide that Labor was planning to borrow more than conservatives to invest. His political argument is that it would make the economy grow faster and the state assets, not just its liabilities.
Ultimately, the calculation that voters are likely to make is to determine who they trust more to manage the economy.
Speaking Thursday on Labor Party plans in Liverpool, McDonnell pledged "an investment of unprecedented scale" to renovate the infrastructure of all parts of the UK.
The Chancellor of the shadow said that he wanted to transfer power and money from southeastern England – and that he would fund his projects through 39; borrowings.
He added that his party would introduce new fiscal rules, which means that "borrowing for investment" would not be included in the borrowing targets.
The movement's economic plan includes doubling "investment" spending, a "social transformation fund" of £ 150 billion and a "green transformation fund" of £ 250 billion.
The Conservatives have also committed to borrow to fund more spending, reformulating their current financial rules.