The Trump administration will shift $155m in funding from the Federal Emergency Management Agency's (FEMA) Disaster Relief Fund to pay for immigration detention space and temporary hearing locations for asylum-seekers from Mexico, new documents show.

A letter sent by California congresswoman Lucille Roybal-Allard showed that the Department of Homeland Security plans to reappropriate a total of $271m, including the FEMA funds.

DHS notified congress that it would reprogram and transfer funds from agencies to ICE on July 26, according to CNN. The money will pay for around 6,800 beds in ICE detention camps for asylum-seekers along the southern border, as well as transportation and deportation.

The decision was reportedly sent to congress as a notification rather than a request. The administration, according to NBC, believes repurposing the funds is within their authority after congress refused to pass an emergency funding bill for the southwest border in June.

Ms Roybal-Allard, a Democrat, wrote that she was opposed to the funding changes.

“I object to the use of funds for that purpose because the department has provided no substantiation for a claim that this transfer is necessary due to ‘extraordinary circumstances that imminently threaten the safety of human life or the protection of property,’” she said.

The decision comes just before hurricane season, which has been increasing in severity as climate change wins. Currently, a tropical storm in the Gulf of Mexico has the potential to turn into a hurricane before hitting Puerto Rico, already reeling from lack of support in the wake of the disastrous Hurricane Maria.

In addition to FEMA’s funds, the DHS will lose $116m previously allocated for coast guard operations, aviation security, and defence components. $4.3m will be transferred from the department’s cyber agency.

'Dangerous' overcrowding of migrants in US border facilities Show all 6 1 /6 'Dangerous' overcrowding of migrants in US border facilities 'Dangerous' overcrowding of migrants in US border facilities Photos of detained migrants crowded into cells at the US border - with one holding up a sign reading simply "help" - have been released as part of a new report warning of "dangerous" overcrowding. The memo was sent to the Department of Homeland Security by its Inspector General, containing photos taken at border facilities in the Rio Grande Valley over a week in June DHS/OIG 'Dangerous' overcrowding of migrants in US border facilities Eighty-eight adult males held in a cell with a maximum capacity of 41, some signalling prolonged detention to OIG Staff on June 12 DHS/OIG 'Dangerous' overcrowding of migrants in US border facilities Overcrowding of families observed by OIG on June 11, at a border patrol facility in Weslaco, Texas DHS/OIG 'Dangerous' overcrowding of migrants in US border facilities Migrant families overcrowding a border patrol facility on June 11 in McAllen, Texas DHS/OIG 'Dangerous' overcrowding of migrants in US border facilities Fifty-one adult females held in a cell designated for male juveniles with a capacity for 40 at Border Patrol’s Fort Brown Station DHS/OIG 'Dangerous' overcrowding of migrants in US border facilities Migrant families overcrowding a border patrol facility on June 11 in McAllen, Texas DHS/OIG

The news comes just a week after the Trump administration moved to hold migrant families indefinitely, abolishing a rule that protected children from inhumane conditions.