A county court debt judgment issued against Boris Johnson is “totally without merit” and the prime minister will apply to have it struck out, Downing Street has said, with officials believing the process could have been started maliciously. The statement came after the official register of county court judgments for England and Wales showed that Johnson had a judgment against him in October last year over an unpaid debt of £535. The register does not give details of to whom the debt is owed. Such a judgment would place the prime minister at risk of not only a bad credit rating but potential enforcement action by bailiffs arriving at Downing Street. In a statement, a Downing Street spokesperson said: “An application will be made for an order to set aside the default judgment, to strike out the claim and for a declaration that the claim is totally without merit.” The statement gave no more details, but No 10 sources said the claim was not for a genuine debt and could have been pursued frivolously or with malice. If a deliberately false claim for debt was made through the courts, this could be a criminal offence. The judgment, issued on 26 October, is for the online county court, whereby people owed a debt can seek recompense through a web-based form, and proceedings can be completed without the alleged debtor ever taking part. However, it is not clear why Johnson did not respond to notices about the case, or if these were sent. The judgment lists the debt as an “unsatisfied record”, meaning it had still not been paid. County court judgments are a late point in a process of seeking redress for a debt, indicating the prime minister would most likely have been contacted via post several times earlier. Unless a debt incurring a county court judgment is paid within 30 days, it is placed on someone’s credit record for six years, making it much more difficult to get loans or mortgages. A creditor can also apply to the county court for a bailiff to collect the debt. However, if the judgment is successfully struck out, no action is taken. The news came amid scrutiny of how Johnson was able to afford to pay for the refurbishment of his Downing Street flat, which reportedly cost up to £200,000, for which he is believed to have paid partly via a loan. The Electoral Commission has begun an inquiry into how the work was funded, saying there were “reasonable grounds” to suspect multiple offences may have been committed. Johnson has previously had to apologise to MPs for the late declaration of more than £52,000 in income.