The US government shutdown is set to stretch into next week after senators voted on Friday for a fourth time to reject a funding fix proposed by President Donald Trump’s Republicans.

Federal agencies have been out of money since Wednesday – with a wide range of public services crippled – as a result of deadlocked talks in Congress on how to keep the lights on.

Tourist sites such as the Washington Monument have closed, key data on employment has been delayed and some official websites have ground to a halt, although other areas of government have yet to be affected.

Some 750,000 employees are likely to be put on furlough – a kind of enforced leave with back pay after the shutdown – as the funding crisis deepens.

Senate leaders have no plans to keep the upper chamber of Congress in session over the weekend, meaning Friday’s vote on a short-term fix was the last chance of the week to end the crisis.

At the centre of the stand-off is a Democratic demand for an extension of healthcare subsidies that are due to expire – meaning sharply increased costs for millions of low-income Americans.