The word "stiffer" is correct and can be used in written English.
You can use it when describing something that is more rigid or difficult than something else. For example: "The teacher implemented stiffer rules for the classroom after the last test."
When sector leaders gather on Thursday at the annual conference of Skills for Care, the workforce development body for adult social care, the talk is likely to be about an even stiffer potential bill, however.
A few hours earlier Sebastian Coe, who is hoping to become the IAAF's president, had made a stiffer, more formal statement in Doha.
Yet even important bills such as the communications data powers or the stiffer controls on strike ballots are essentially secondary in political terms.
The twin passes are often crossed on the same journey – from Little Langdale to Eskdale – but Alfred Wainwright warned that drivers who have come over Wrynose from the east must expect "a much stiffer climb" over Hardknott and should approach it with "the utmost concentration".
However, critics wants stiffer penalties for those who fail to comply.
But the iPhone is facing much stiffer competition from handsets using Google's popular Android operating system.
The first is the banks' own efforts to deleverage, either to shed money-losing operations and assets or to meet stiffer capital requirements.
Being identified as a gang-member can be a serious black mark, warranting a stiffer than average sentence for any crime.
Sentences got stiffer; Bertie Smalls, an armed robber turned "supergrass", informed on dozens of London's criminals.
Competition is stiffer than elsewhere in the country, too.
These areas will benefit from continued growth in China, while for the euro zone it may signify stiffer industrial competition from abroad.
