Chief constables and police and crime commissioners in Wales want fines issued for breaching lockdown rules to be the same as England.
Fines in Wales are £60 but now start at £100 in England.
In a letter to the first minister, they said there has been "cross-border confusion" and more people travelling into Wales for exercise where rules are different.
A Welsh Government spokesperson said it was keeping the fines under review.
First Minister Mark Drakeford has told those thinking about a weekend trip to Wales: "Don't do it".
The letter sent on Friday by the Policing in Wales group said officers in Gwent force area reported "clear community concerns" around the recreational laws in England leading to members of the public crossing the border for cycling or walking.
In Wales, people have to exercise close to home, whereas those in England can travel further afield, although they have been advised to avoid Wales for the time being.
The letter said "there is growing evidence that adherence to the regulations is weakening in some areas".
It said there was "public confusion" around the divergence in regulations between the UK and Welsh Governments regarding fines and lockdown rules.
It said: "Policing in Wales welcomes the continued engagement with both your government and officials in order to assist in the shaping of the approach to Covid 19 regulations.
"With this in mind we are writing to request that you consider aligning the fines structure.... with the revised levels announced by the UK prime minister on Sunday May 10.
"Chief constables and police and crime commissioners feel that this would provide parity and consistency across England and Wales, obviating any cross-border confusion on this point that may exist.
"It will also provide clarity for people living in our communities across Wales, who will know that their local officers and staff have exactly the same powers and sanctions as their colleagues working over the border."
@MarkDrakeford @fmwales has declined to increase the #COVID19 fines because he claims there is no evidence that they will work and is calling for evidence.— Arfon Jones 🏴🏴🌈🌈 (@ArfonJ) May 16, 2020
Feel free to submit evidence or comment via the following:
A Welsh Government spokesperson said: "We are keeping the fines under review and working with the police forces in Wales to ensure they have the appropriate powers they need to enforce the lockdown regulations."
Plaid Cymru leader Adam Price said: "All four chief constables and all four of Wales' police and crime commissioners are united in agreement that raising the fines for those breaking lockdown rules in Wales - and bringing them in parity with England, is the right step to allow them to better protect our communities during this crisis.
"The first minister has all the evidence he needs and should act now - today - before this weekend is over."